Учебное пособие для студентов радиотехнического факультета "Reader for Second-Year Students of Radioengineering Department (Part 1)"

Министерство образования и науки Украины

Донецкий национальный технический университет

Белянская Н. Г. Шкарупа О. Г.

Reader for Second-Year Students of Radioengineering Department

(Part 1)

Пособие для студентов второго курса радиотехнического факультета

(Часть 1)

Донецк, ДонНТУ, 2007

Министерство образования и науки Украины

государственное высшее учебное заведение

Донецкий национальный технический университет

Белянская Н. Г. Шкарупа О. Г.

Reader for Second-Year Students of Radioengineering Department

(Part 1)

Пособие для студентов второго курса радиотехнического факультета

(Часть 1)

Утверждено на заседании

кафедры английского языка

протокол № 10 от 19.06.2007

Утверждено советом ИМС

протокол № 26 от 27.11.2007

Пособие для студентов второго курса радиотехнического факультета. – Донецк: ДонНТУ, 2007. – 104 стр.

Составители: Белянская Н. Г. Шкарупа О. Г.

Рецензенты: декан радиотехнического факультета д. п. н., п профессор Стефаненко П. В.

заведующий кафедрой радиотехники и защиты

информации к.т.н., доцент Паслён В. В.

© Донецкий национальный технический университет

Содержание

Введение ………………………………………………………..5

UNIT 1. Radio and its Application……………………………..6

UNIT 2. Marconi………………………………………………15

UNIT 3. Popov…………………………………………………22

UNIT 4. Radio Waves.………………………………………...29

UNIT 5. Electronics……………………………………………37

UNIT 6. Integrated Circuits….………………………………...46

UNIT 7. Semiconductors….……………………………………56

UNIT 8. Lasers…...………….…………………………………63

UNIT 9. Telecommunication..…………………………………73

UNIT 10. Wireless Communication…………..………………..82

Additional texts ……………………………………………….92

Abbreviations …………………………………………………..103

Введение

Данное пособие предназначено для студентов второго курса радиотехнического факультета.

Целью пособия является развитие у студентов навыков чтения и понимания научно-технической литературы на материале текстов научно-популярного характера и подготовка студентов к чтению и пониманию оригинальной технической литературы по специальности на 3 и 4 курсах. Также пособие ставит задачу развить у студентов необходимые навыки устного общения на английском языке в объёме материала, предусмотренного программой. С этой целью даны разнообразные упражнения лексического и грамматического характера.

Пособие состоит из 10 уроков. Каждый урок включает в себя основной текст (А) и дополнительный (В).

На базе текста А разработаны предтекстовые и послетекстовые упражнения, даны технические термины, встречающиеся в тексте и их перевод на русский язык. Послетекстовые упражнения ставят цель снять лексико-грамматические трудности при чтении текста.

Текст В предназначен для чтения и перевода на русский язык и для краткой передачи содержания текста на английском языке.

Кроме того, в конце каждого урока студентам предлагается тема для обсуждения проблем, рассмотренных в текстах А и В.

Тексты составлены на основе оригинальной английской и американской научно-технической литературы.

UNIT 1

Topic: Radio and its Application

Text A. Invention of Radio is Contribution of Many Sciences

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

disturbance – возмущение

means of propagating – способ распространения

arouse – вызывать

transmitter – радиопередатчик

electromagnetic wave – электромагнитная волна

perceive – воспринимать, ощущать

unobservable – невидимый

straight – прямой

velocity – скорость

oscillate – колебаться, выбрировать

frequency – частота

crest – гребень (волны)

wavelength – длина волны

related – взаимосвязанные

divide – делить

Exercise 2. Repeat and translate into Russian the following words.

1. with one stress or the stress on the first syllable:

message, cycle, audio, light, vehicle, physicist, tube, rapidly, similar, cordless, energy, current, type, maximum, frequency, mobile, solar, chemical, guide, quasar, pulsar, neutron.

2. with the stress on the second syllable:

research, device, velocity, observe, prediction, occur, considerable, transmit, disturbance, detect, excitement, phenomenal, equipment, determine, perceive, produce, invention, remarkable, astronomy.

3. with two or more stresses:

application, entertainment, experimental, mathematically, electromagnetic, transatlantic, unobservable, garage-door (openers), radio-operated, communication, electronic, satellite, navigation, exploration, commemorate, oscillate, propagate, radiate, demonstrate.

Exercise 3. Study the text and try to understand all details.

Invention of Radio is Contribution of Many Sciences

Early in the 19^th century, Michael Faraday, an English physicist, demonstrated that an electric current can produce a local magnetic field and that the energy of this field will return to the current when the current is stopped or changed. James Clerk Maxwell, professor of experimental physics at Cambridge, in 1864 proved mathematically that any electrical disturbance could produce an effect at a considerable distance from the point at which it occurred and predicted that electromagnetic energy could travel outward from a source as wave moving at the speed of light.

At the time of Maxwell’s prediction there was no known means of propagating or detecting the presence of electromagnetic waves in space. It was not until about 1888 that Maxwell’s theory was tested by Heinrich Hertz, the famous German physicist, who demonstrated that Maxwell’s predictions were true at least short distances.

Radio aroused worldwide excitement in December 1901, when Guglielmo Marconi, the Italian physicist, received the first transatlantic radio signals in St. John’s, Newfoundland, sent from a transmitter in England.

Radio messages and signals travel across space by way of electromagnetic waves. Light is another type of electromagnetic wave, as are X

rays, gamma rays, and cosmic rays. Since it is difficult for humans to perceive the action of these unobservable waves, electromagnetic wave action is often compared to that of water waves. Like water waves, radio waves also radiate away from a center. They can travel through a vacuum. Like light waves radio waves travel in straight lines at a velocity of about 300,000 kilometers (186,000 miles) per second and have amplitudes that vary cyclically with time; that is they oscillate from a zero amplitude to a maximum and back again. The number of times the cycle is repeated in one second is called the frequency in cycles per second, and the time taken to complete one cycle is sometimes called the period. To commemorate Heinrich Hertz a frequency of one cycle per second is called one hertz. The distance from one wave crest to the next is known as the wavelength. Wavelength and frequency are related. Dividing the speed of the electromagnetic wave by the wavelength gives the frequency.

From 1920 onward radio made phenomenal progress through research activities in Europe, North America, and Asia. The invention of the electron tube and later the transistor (1948) made possible remarkable developments.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Electrical disturbance, considerable distance, source, speed, outward, detect, transmitter, electromagnetic wave, velocity, oscillate, frequency, wavelength, research.

Exercise 2. Find the equivalents of the following words and word-combinations in the text.

Исходить из центра; вызвало всеобщий интерес; циклично варьируют по времени; воспринять действие этих невидимых волн; двигаться со скоростью света; частота оборотов в секунду; расстояние от гребня одной волны до гребня другой; средства передачи и обнаружения электромагнитных волн в пространстве; распространяться в воздушной среде и вакууме; разделить скорость электромагнитной волны на длину волны; колебаться от нулевой амплитуды до максимума и обратно.

Exercise 3. Match the words with their definitions:

word

definition

1. transmitter

2. satellite

3. technology

4. research

5. frequency

6. radiate

7. propagate

8. source

9. relay

1. device which receives messages, radio programmes, and transmits them with greater strength, thus increasing the distance over which they are carried.

2. place from which something comes or is got

3. send out rays of light or heat

4. transmit, extend the operation

5. comparatively small body moving in orbit round a planet

6. study, mastery and utilization of manufacturing and industrial methods

7. number of repetitions in a given time

8. investigation undertaken in order to discover new facts

9. part of a telegraph or radio apparatus for sending out signals, messages, music, etc.

Exercise 4. Arrange the words of the two groups in pairs:

1. with a similar meaning

1. happen

2. speed

3. receive

4. devise

5. considerable

6. unobservable

7. spread

8. similar

9. show

10) detect

11) occupation

12) oscillate

13) cordless

14) join

15) observe

1. alike;

2. vibrate;

3. notice;

4. propagate;

5. wireless;

6. piece together;

7. demonstrate;

8. velocity;

9. profession;

10. occur;

11. obtain;

12. important;

13. perceive;

14. invent;

15. imperceptible

b) with contrary meaning

1. different

2. transmitter

3. earliest

4. inward

5. easy

6. absence

7. standing

8. finally

9. leave

10) low

11) near

12) rapidly

13) dim

14) visible

15) detailed

1. clear;

2. return;

3. unobservable;

4. slowly;

5. primarily;

6. essential;

7. distant;

8. difficult;

9. presence;

10. similar;

11. receiver;

12. high;

13. latest;

14. moving;

15. outward;

Exercise 5. Use the word in brackets to form a word that fits in the space.

1. During … the transistor becomes heated. (to operate)

2. A … antenna is a device that projects the radio frequency energy into space. (to transmit)

3. A transistor is … of current, the vacuum tube, in contrast, … of voltage. (to amplify)

4. A radio wave is a special … of electric and magnetic force. (to combine)

5. Many stations can operate in the same region without … if their frequencies are different. (to interfere)

6. Listeners receive the station they want by tuning their … to the station’s frequency. (to receive)

7. The … were always correct provided the necessary instruments were used. (to measure)

8. The sky wave from a very … transmitter can be reflected several times between the ionosphere and the Earth. (power)

9. There is a very important … between frequency and wavelength. (to relate)

Exercise 6. Translate the 4^th paragraph of the text.

Exercise 7. Read the text and answer the questions.

1. What demonstrations did Michael Faraday make at the beginning of the 19^th century?

2. What is the essence of Maxwell’s prediction?

3. Why couldn’t his theory be proved in those days?

4. When did the radio signals cross the ocean?

5. What other types of electromagnetic waves can you name?

6. What is the speed of travel of radio waves?

7. In what way could you define the frequency and wavelength?

8. How are they related?

9. When did radio make phenomenal progress?

Exercise 8. Say whether the following statements are true or false.

1. Michael Faraday was the first to notice the existence of a local magnetic field produced by an electric current.

2. James Maxwell proved experimentally that electromagnetic energy could travel outward from a source.

3. Maxwell’s theory was tested by H. Hertz in 1888.

4. The first transatlantic radio signals were received early in the 20^th century.

5. X rays, gamma and cosmic rays are not the type of electromagnetic waves.

6. The number of times the cycle is repeated in one second is called the period.

7. Dividing the frequency of the electromagnetic wave by the wavelength gives the speed.

Exercise 9. Complete the following sentences choosing the most suitable variant.

1. Guglielmo Marconi, the Italian physicist, … the first transatlantic radio signals in St. John’s Newfoundland. (transmit, receive, detect, produce)

2. Electromagnetic energy can travel outward from a … as waves moving at the speed of light. (point, way, field, source)

3. Maxwell’s prediction was … by H. Hertz, the famous German physicist. (obtain, compare, send, test)

4. The energy of this field will … to the current when the current is stopped or changed. (come back, occur, start, leave)

5. Heinrich Hertz demonstrated that Maxwell’s prediction were … .(wrong, known, correct, considerable)

6. Wavelength and frequency are … .(relay, rotate, relate, remove)

7. The … of the electron tube and later the transistor made possible remarkable developments. (find, discovery, invention, opening)

Exercise 10. Develop the following ideas. Use the words and word-combinations provided in brackets.

1. The invention of the radio is the contribution of many scientists.

(to attract everyone’s attention, to show the existence of a magnetic field, to spread out from…, radio waves bridge the Atlantic, to instrument for transmission or perception…, make an impression at a large distance, to compare them to light waves, Maxwell’s ideas were checked…)

2. The nature of radio waves.

(different kinds of electromagnetic waves, to be transmitted across…, to achieve extraordinary results, the relationship between frequency and wavelength, to make one full cycle, to be propagated through …, electromagnetic waves can’t be perceived by man’s senses, to be generated from a central position)

Exercise 11. Give a summary of the text.

Exercise 12. Speak about the story of radio and its basic physical properties.

Text B.

Exercise 1. Read and entitle the text. Answer the following questions.

1. What applications of the radio can you find in your home?

2. What other applications of the radio apart from those mentioned in the text can you remember?

In the earliest practical application, radio was used primarily to exchange messages with ships at sea. Radio is still used for this purpose and for communication across oceans.

Television, one of the most popular form of the entertainment in the home, is actually a kind of radio. It uses special equipment for sending and receiving pictures in the form of radio signals. The television audio signals are received by equipment similar to that used in other forms of radio. Other home devices that use radio technology are cordless telephones, garage-door openers, and radio-operated toy airplanes and cars.

Radio technology has other uses outside the home. It provides a means of instant communication with moving vehicles such as taxicabs, service trucks, squad cars and motorcycles. Observers in airplanes can report traffic violations, accidents and traffic jams by radio to police officers on the ground. Many people in the medical profession have beepers – portable electronic device used to page the person who carries out.

In radio telephones such as cellular mobile phones, voice signals are sent across town or over long distances by high-frequency radio signals called microwaves. Land based microwave relay stations and communication satellites orbiting the Earth receive and transmit the microwave signals.

With radio to guide them, airplane pilots can fly through fog or storm and land safely at airports. Pilots and ship captains use radio navigation systems to determine their locations and stay on course.

Radio technology is also essential to space exploration. Space probes use radio waves to relay information about the solar system. Radio astronomy is used to detect celestial objects too distant and dim to be seen by optical telescopes. It can also be used to determine the chemical make up of stars and gas clouds and the speed and direction of moving stars. Using radio astronomy, quasars were discovered in the early 1960s. Pulsars, believed to be rapidly rotating neutron stars, were discovered later in the decade. With the information obtained scientists can piece together the puzzle of how the universe began.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Put 6 questions to the text.

Exercise 3. Retell the text.

Exercise 4. Speak on the following topic: “Application of radio in everyday life”.

UNIT 2

Topic: Marconi

Text A. Marconi and His Invention

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

transmission – передача

reception – приём

transoceanic – трансокеанский

wireless message – радиосигнал, радиосообщение

distinctness – ясность, отчётливость

sensitive – чувствительный

receiver – приёмник

communication – связь, системная связь

preliminary – предварительный, подготовительный

adjust – настраивать, регулировать

hitch – помеха, препятствие

Exercise 2. Study the following words and choose:

nouns:

1. a) oscillator; b) oscillatory; c) oscillate; d) oscillation;

2. a) transmit; b) transmission; c) transmitter; d) transmissible;

3. a) operation; b) operating; c) operator; d) operative;

4. a) apply;b) applied; c) applicant; d) appliance;

adjectives:

1. a) frequency; b) frequentative; c) frequent; d) frequency;

2. a) cycle; b)cyclist; c) cyclical; d) cyclically;

3. a) voice; b) voiced; c) voiceless; d) voicelessly;

4. a) observe; b) observer; c) unobservable; d) observation.

Exercise 3. Study the text and try to understand all details.

Marconi and His Invention

Italian electrical engineer Guglielmo Marconi was the first to create a practical system communicating over long distances using radio signals. New reports in issues o f Scientific American from 1902 to 1903 recorded Marconi’s first successful transmissions and receptions of radio signals across the Atlantic Ocean.

Here are some abstracts from news reports published in “Scientific American”.

The Marconi Transoceanic Experiments

January 4, 1902

The Scientific American is enabled to present to its readers the first photographs that have been taken of Marconi’s station at Signal Hill, Newfoundland – a station which will hereafter be memorable as the first place where a transoceanic wireless message was received.

That the signals were received can hardly be doubted. Marconi himself has publicly stated that the signals were heard with certainty and distinctness. At the Signal Hill station a receiving wire was employed about 400 feet high, which was supported by a kite. At Cornwall, the transmitting station was provided with an apparatus which was much more powerful than that previously used for communicating at distances of 200 miles. Even with a transmitter of increased power, the signals were heard only with the aid of a most sensitive telephone receiver.

The announcement of his success has earned for Marconi a popularity which is not the fortune of all inventors. The Canadian government has determined to stand by him in his fight against the Anglo-American Cable Company. Officials have honored him everywhere.

Marconi Sends Messages Across the Atlantic

January 3, 1903

It is now authoritatively announced by Marconi, himself, that wireless messages have been transmitted between the Old and the New World Messages were sent from Lord Minto, Governor-General of Canada, and from Marconi, to King Edward. Messages were likewise sent to the King of Italy, by Marconi and by Commander Martino of the Italian cruiser "Carlo Alberto"; other messages were from Dr. Parkin to the London Times, and from Richard Cartwright of Canada to the Times.

Marconi states that it was about a month ago that he succeeded in transmitting messages from Table Head to Cornwall. First, the messages were all in code and were simple queries, such as "How is this?"

In many respects this achievement of Marconi is fully equal to that of Cyrus Field in opening communication between America and England by means of the submarine cable. But the distance covered by Marconi is greater than that over which the first submarine cable extended, by about 300 miles. So far as practical results are concerned, the Anglo-Italian inventor may well be regarded as the pioneer of commercial wireless telegraphy. Where others have failed he has succeeded.

The First Wireless Message from the United States to England

January 31,1903

On the night of January 18, Marconi succeeded in outdoing himself when he transmitted a message of greeting from President Roosevelt to King Edward VII directly from the Cape Cod station to Poldhu, England. The distance covered is greater by 600 miles than that over which messages have previously been sent.

The performance is all the more remarkable when it is considered that the message was sent without any previous attempt to establish communication by preliminary signals.

Marconi's success came unexpectedly. After having busied himself all day in preparing his sending apparatus, he began to practice sending President Roosevelt's message without calling either the Poldhu or the Glace Bay station, contrary to the arrangements which he had made. Thinking that he might not be able to get the English station for a day or two, he decided to send the President's message by way of the Glace Bay station. Calling up the operator there he gave him the message with instructions to forward it to England. To Marconi's astonishment he received a reply from Glace Bay that the operator had been informed by the station at Poldhu that the message had been received directly from Cape Cod. There was not the slightest hitch in the process of sending. About four minutes were required to transmit the entire message.

King Edward replied to the message which he received from the President by cable.

The King sent his message by cable for the reason that Marconi was adjusting his instrument for sending tests to England and did not wish to upset his plans by making any attempt at receiving from the other side of the ocean.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Communication, successful transmission, transoceanic wireless message, with certainly and distinctness, a receiving wire, announcement, commercially, enormous cheapening, submarine cable, establish, take advantage of, unexpectedly.

Exercise 2. Find the equivalents of the following words and word-combinations in the text.

Передающая станция, практическая система связи, не подлежит сомнению, воздушный змей, решиться, беспроволочный телеграф, закодированы, подводный кабель, превзойти самого себя, усовершенствовать, нарушать планы, потерпеть неудачу, настраивать (регулировать).

Exercise 3. Match the words with their definitions:

word

definition

1. radar

2. invention

3. system

4. receiver

5. signal

6. telegraph

7. transmitter

8. aerial

9. radio

10)television

a) a machine or system that has been invented by someone.

b) a system of sending sound over a distance using electrical signals.

c) a piece of wire that receives television or radio signals.

d) a piece of equipment used for sending radio signals or for broadcasting programmes

e) a system of sending pictures and sounds by electrical signals over a distance so that people can receive them on a television set.

f) is used to refer to a set of equipment, parts, or devices, for example a hi-fi or computer.

g) a way of discovering the position or speed of things that cannot be seen, using radio signals.

h) a series of sound or light waves which carry information.

i) a system of sending messages over long distances by means of electrical or radio signals.

j) a part of a telephone that you hold near to your ear and speak into; or a radio, or а television set

Exercise 4. Complete the following sentences and translate them into Russian.

1. … a receiving wire was employed about 400 feet height …

2. … the signals were heard only with the aid of …

3. … the messages were all in code and …

4. But the distance … by about 300 miles.

5. … without any previous attempt to establish communication …

6. … he gave him the message with instructions …

7. … in the process of sending.

Exercise 5. Translate the 3 and 4^th paragraphs of the text.

Exercise 6. Put as many questions as possible to the first sentence of the text.

Exercise 7. Define whether the following statements are true or false and correct the false ones.

1. News reports in issues of “American Science”, from 1902 to 1903 recorded Marconi’s first successful transmission of radio signals across the Atlantic Ocean.

2. At Cornwall, the receiving station was provided with an apparatus which was much more powerful than the previously used one.

3. The Canadian government has determined to stand by him in his fight against the Anglo-American Cable Company.

4. The distance covered by Marconi is greater than that over which the first submarine cable extended.

5. Marconi transmitted a message of greeting from President Roosevelt to King Edward VI.

6. About forty minutes were required to transmit the entire message.

7. The King sent his message by cable because he didn’t want to upset Marconi’s plans who was adjusting his instrument for sending tests to England.

Exercise 8. Write a summary of the text.

Text B.

Exercise 1. Read the text. Which of the following titles is the best?

Today we don't think twice when we turn on the radio, but when a 21 -year-old Italian invented it over 100 years ago no one could believe their ears.

One day in 1895 in Bologna, Italy, an Italian engineer sent the world's first radio signal. Using a simple radio transmitter and a receiver, he sent a signal from his attic room to his brother who was hidden in a field a kilometer away. When his brother received the signal he fired a gun. The Italian government showed no interest in young Marconi's invention, but his mother believed he had a good idea. So in February of the following year, she sent him to England to meet her cousin who was an important engineer. It was a journey that would change the world.

In England, this engineer and his cousin were joined by two other inventors. In 1897 he formed the Wireless Telegraph Company in London and started to transmit simple radio signals over long distances. In 1899 he sent the first wireless telegraph across the English Channel to France. They were transmitted from Poldhu in Cornwall, and were received 3,520 kilometers away in St John's, Newfoundland, using an aerial flown in the air by a kite.

He had always believed that radio waves could travel round the curve of the earth. By 1901 he had improved his radio system so much that on 12^th December he astonished the world by sending the first radio signals across the Atlantic Ocean.

This meant that ships were now able to send messages from ship to shore if they were in distress. His system was soon adopted by the British and Italian navies. From now on, his company had the monopoly of wireless communication and he became a multi-millionaire.

This engineer is one of the key figures of the twentieth century. He even recognized the military importance of radar and thought of the idea of sending radio signals out into space. When he died in 1937, wireless stations all over the world closed down for two minutes as a mark of respect. He made only one big mistake. He thought that television would never become popular.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Choose the best answer to these questions according to the text.

1. What important event happened in Bologna in 1895?

2. Why did Marconi’s mother send him to England?

3. Where did Marconi send his first telegraph?

4. What astonished the world in 1901?

5. What mistake did Marconi make?

Exercise 3. Retell the text.

Exercise 4. Speak on the topic: “Marconi’s successful experiments in transmitting messages”.

UNIT 3

Topic: A. Popov and His Invention

Text A. A. Popov

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

inventor – изобретатель

record – записывать, регистрировать

generate – генерировать, производить

lightning discharge – грозовой разряд, молния

wire – провод, проводник

range – диапазон, дальность действия

device – прибор, устройство

transmit – передавать

oscillation – колебание, вибрация

wireless – беспроводной, радио

audible – звуковой, слышимый

Exercise 2. Match the following words with their translation.

I) 1) invent; 2) inventor; 3) invention; 4) inventive;

a) изобретение; b) изобретательный; c) изобретать; d) изобретатель;

II) 1) light; 2) lighten; 3) lighter; 4) lighting; 5) lightning;

a) зажигалка; b) освещать; c) молния; d) освещение; e) свет;

III) 1) receive; 2) receivable; 3) receiver; 4) received;

a) радиоприёмник; b) принимать; c) общепринятый; d) годный к принятию;

IV) 1) prefer; 2) preferable; 3) preferably; 4) preference; 5) preferential;

a) предпочтение; b) предпочитать; c) предпочтительный; d) предпочтительно; e) пользующийся предпочтением;

V) 1) produce; 2) producer; 3) producible; 4) production; 5) productive;

a) производство; b) производящий; c) производить; d) производимый; e) производитель;

VI) 1) transmit; 2) transmitter; 3) transmission; 4) transmissible;

a) радиопередатчик; b) передавать; c) передающийся; d) передача;

A. Popov

A.S. Popov, the great Russian inventor, was born in 1859. By the time he graduated from Petersburg University (1882) he had already possessed a broad knowledge of electrical theory as well as a wide experience in that field.

Working both as scientist and teacher, he always carried on some practical work, solving many practical problems such as the introduction of electricity into the Navy and others. Popov was one of the first to pay attention to the works of Hertz who proved by experiments the existence of electromagnetic waves. After many experiments carried out together with his assistant Ribkin the device Popov constructed began receiving electromagnetic waves at a long distance. By means of his receiver Popov could detect the waves at a distance of some meter and then kilometers. The receiver recorded waves generated by lightning discharges. While experimenting the scientist found out that a free wire being connected to the receiver, the range of the latter increased. Thus he connected his first receiver to the first antenna.

On April 25, 1895, Alexander Popov demonstrated his device at the Russian Physico-Chemical Society. Having summarized the results of his experiments, Popov expressed his hope that the device, after being perfected, would make possible transmitting signals at a distance by means of rapid electrical oscillations. In summer 1895, Popov’s invention was successfully tested and in the same year he attached to the device an apparatus previously used for recording telegrams over the wire telegraph. In the following year this receiver was used at the electric power station in Nizhny Novgorod for warning about approaching thunderstorm.

The great Russian inventor didn’t make any secret of his discovery, describing it in the press and making reports about it at the meetings of scientific societies. In the same year he demonstrated the transmissions of words over a wireless telegraph. This new demonstration proved to be of great importance.

In summer 1897, Popov successfully carried out his experiments at sea, having succeeded in effecting radio communication between the shore and the sea at a distance of 3 klm.

In this way the future wireless communication between the continents was being prepared. The year 1898 witnessed a new important invention made by Popov together with his assistants Ribkin and Troitsky, namely the reception of audible signals by means of a receiver. All these successful experiments having been completed, serious practical testing began. Popov’s radio telegraph helped to save the battleship “General Admiral Apraksin”.

Popov’s work drew attention in many countries. The wireless telegraphy is the result of Popov’s experiments, this fact having been acknowledged by different representatives of foreign science, engineering and industry. Popov was offered immense profits from commercial use of his invention in case he leaves Russia. But the Russian patriot refused the wealth offered to him, preferring to remain a true son of his fatherland “I am a Russian and I must give all my knowledge, all my work and all my achievements to my native land” were his words.

(Source: Briskina K. Zavadskaja M. English for technical students. Kiev 1977. pp. 16-17)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Discharge, carry on, long distance, receiver, record, increase, oscillation, previously, thunderstorm, wireless telegraph, discovery.

Exercise 2. Find English equivalents of the following words and word-combinations in the text.

Решать, диапазон, прибор, усовершенствовать, звуковой сигнал, предлагать, передача, успешно испытать, важность, проводить эксперимент, привлечь внимание, признавать, огромный.

Exercise 3. Match the words with their definitions.

word

definition

1. invent

2. experience

3. experiment

4. generate

5. receiver

6. wire

7. carry out

1. test or trial carried out carefully in order to study what happens and gain new knowledge

2. produce

3. metal in the form of a thread

4. complete something

5. create or design something not existing before

6. apparatus for receiving signals

7. process of gaining knowledge or skill by doing and seeing things

Exercise 4. Complete the following sentences and translate them into Russian.

1. … Popov could detect the waves …

2. … invention was successfully tested.

3. … this receiver was used …

4. … over a wireless telegraph.

5. The year 1898 witnessed …

6. … from commercial use of his invention …

7. … I must give all my knowledge, all my work …

Exercise 5. Put the words in the correct order.

1. Receiver, electromagnetic waves, at, distance, his, could, long, a, his device.

2. Discharges, waves, the receiver, generated, recorded, by, lightning.

3. Was, in, 1895, tested, his, summer, invention, successfully.

4. Scientific societies, Popov, discovery, made, his, at, meeting, the, reports, about, of.

5. Countries, drew attention, many, in, work, his.

Exercise 6. Put as many questions as possible to the last sentence of the third paragraph.

Exercise 7. Translate the second and the third paragraphs of the text.

Exercise 8. Find in the text the sentences with Participles in the function of an adverbial modifier. Translate the sentences into Russian.

Exercise 9. Translate the following sentences with Absolute Participial Construction into Russian.

1. The experiment being over, the reporters attacked the young scientists with questions.

2. The question being difficult, I had to think for a moment.

3. This scientist worked much to perfect his invention, his scientific achievements being highly appreciated all over the world.

4. The device having been carefully tested, we put it into operation.

5. The direction of the current being reversed in the conductor, the direction of the needle is similarly reversed from its former position.

6. A series of experiments having been completed, I. Kurchatov launched Europe’s first cyclotron at the Radio Institute.

7. Many chemical and organic compounds are semiconductors, their conductivity increasing with heating and falling with cooling.

Exercise 10. Define whether the following statements are true or false and correct the false statements.

1. When A. Popov graduated from Petersburg University he was quite experienced in electrical theory.

2. Popov solved many theoretical problems such as the introduction of electricity into the Navy.

3. By means of his receiver Popov could detect the waves at a distance of some kilometers.

4. Popov was the first to connect the receiver to the antenna.

5. Popov kept his discovery in secret.

6. In 1899 the reception of audible signals was fulfilled by means of a receiver.

7. The invention of the wireless telegraphy by Popov is acknowledged all over the world.

Exercise 11. Write a summary of the text.

Text B.

Exercise 1. Read and entitle the text.

Radio occupies one of the leading places among the greatest achievements of modern engineering. It was invented by Professor A.S. Popov, who demonstrated the first radio-receiving set in the world on May 7, 1895. And it is on this day that we mark the anniversary of the birth of the radio.

By his invention Popov made a priceless contribution to the development of world science.

A.S. Popov was born in the Urals, on March 16, 1859. For some years he had been studying at the seminary in Perm and then went to the University of St. Petersburg. In his student days he worked as a mechanic at one of the first electric power-plants in St. Petersburg which was producing electric lights for Nevsky prospect.

After graduating from the University in 1882, A.S. Popov remained there as a post-graduate at the Physics Department. A year later he became a lecturer in Physics and Electrical Engineering in Kronstadt. By this time he had already won recognition among specialists as an authority in this field.

After Hertz had published his experiments proving the existence of electromagnetic waves, A.S. Popov thought of a possibility of using Hertz waves for transmitting signals over a distance. Thus the first wireless (radio) receiving set was created. Then Popov developed his device and on March 24, 1896 he demonstrated the transmission and reception of a radiogram consisting of two words: Heinrich Hertz. On that day the radio-telegraphy was converted from an abstract theoretical problem into a real fact.

Popov’s invention laid the foundation for further inventions and improvements in the field of radio engineering. Since that time scientists all over the world have been developing the modern systems of radio-telegraphy, broadcasting, television, radiolocation, radio navigation and other branches of radio electronics.

Radio will find still greater applications in many fields of science and technology.

(Source: Andrianova L. Bagrova N. Ershova E. English. Moscow. 1988. pp. 13-14)

Exercise 2. Put 5 questions to the text.

Exercise 3. Retell the text.

Exercise 4. Speak on the following topic: “A. Popov’s role in the development of radio engineering”.

UNIT 4

Topic: Radio Waves

Text A. Essential Properties of Radio Waves

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

at right angle – под прямым углом

plane of polarization – плоскость поляризации

alternating current – переменный ток

wavelength – длина волны

relation – соотношение, зависимость

equation – уравнение

strength – сила, напряжённость, интенсивность

measure – измерять

interference – помеха

intelligible – информационный, разборчивый

broadcast station – радиопередающая станция

wave front – волновой фронт, фронт импульса

flux – поток

reverse – изменять (направление), реверсировать

Exercise 2. Match the following words with their translation.

I) 1) direct; 2) direction; 3) directional; 4) directly; 5) directory;

a) направленный; b) справочник; c) прямой; d) направление; e) прямо;

II) 1) energy; 2) energetic; 3) energetics; 4) energize;

a) энергичный; b) питать энергией; c) сила, мощность; d) энергетика;

III) 1) divide; 2) divided; 3) dividing; 4) divider; 5) division;

a) разделяющий; b) делить; c) раздельный; d) деление; e) делитель;

IV) 1) measure; 2) measurable; 3) measureless; 4) measurer; 5) measurement;

a) измерение; b) измерительный прибор; c) измерять; d) безмерный; e) измеримый;

V) 1) locate; 2) location; 3) locality; 4) local; 5) locator;

a) местность; b) искатель; c) определение местонахождения; d) местный; e) определять местонахождение;

VI) 1) pole; 2) polar; 3) polarity; 4) polarize; 5) polarization;

a) полярный; b) поляризовать; c) поляризация; d) полюс; e) полярность;

Radio Waves

Electrical energy that has escaped into free space exists in the form of electromagnetic waves. These waves, which are commonly referred to as radio waves, travel with the velocity of light and consist of magnetic and electrostatic fields at right angles to each other and also at right angles to the direction of travel. One-half of the electrical energy contained in the wave exists in the form of electrostatic energy, the remaining half being in the form of magnetic energy.

The essential properties of a radio wave are the frequency, intensity, direction of travel, and plane of polarization. The radio waves produced by an alternating current will vary in intensity with the frequency of the current and will therefore be alternately positive and negative. The distance occupied by one complete cycle of such an alternating wave is equal to the velocity of the wave divided by the number of cycles being sent out each second and is called the wavelength.

The relation between wavelength λ in meters and frequency f in hertz per second is therefore

λ = 300,000,000 ,

f

the quantity 300,000,000 being the velocity of light in meters per second.

The frequency is ordinarily expressed in kilohertz, abbreviated kHz, or in megahertzs, abbreviated mHz. A low frequency wave is seen from the above equation to have a long wavelength, while a high frequency wave corresponds to a short wavelength.

The strength of a radio wave is measured in terms of the voltage stress produced in space by the electrostatic field of the wave and is usually expressed in microvolts stress per meter.

The minimum field strength required to give satisfactory reception of the radio wave varies with the amount of interference that is present. Under the most favourable conditions it is possible to obtain intelligible signals from waves having a strength as low as 0.1 mv per meter, but ordinarily interfering waves generated by both man-made and natural sources draw out such weak radio signals and make much greater field strengths necessary. Thus experience has shown that in rural areas a field strength in the order of 100 mv per meter is required to give what the listener considers satisfactory service from a broadcast station, while in urban locations, where the man-made interference is much greater, a field strength of 5000 to 30,000 mv per meter is needed to insure good reception at all times.

A plane parallel to the mutually perpendicular lines of electrostatic and electromagnetic flux is known as the wave front. A wave always travels in a direction at right angles to the wave front, but whether it goes forward or backward depends upon the relative direction of the lines of electromagnetic and electrostatic flux. If the direction of either the magnetic or electrostatic flux were reversed, the direction of travel would be reversed, but reversing both sets of flux has no effect.

The direction of the electrostatic lines of flux is called the direction of polarization of the wave. If the electrostatic flux lines are vertical, the wave is vertically polarized; when the electrostatic flux lines are horizontal and the electromagnetic flux lines are vertical, the wave is horizontally polarized.

(Source: Briskina K. Zavadskaja M. English for technical students. Kiev 1977. pp. 238-240)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Refer, consist of, travel, essential, vary, relation, abbreviated, wavelength, intelligible signals, forward, backward, reversed, voltage stress.

Exercise 2. Find English equivalents of the following words and word-combinations in the text.

Угол, свойство, приём, искусственный, слабые радиосигналы, содержать, измерять, напряжённость поля, электромагнитный поток, радиопередающая станция, частота.

Exercise 3. Match the words with their definitions.

word

definition

1. angle

2. velocity

3. quantity

4. equal

5. measure

6. broadcast

7. flux

8. reverse

1. amount, total or number

2. find the size, extent, volume, degree, etc.

3. cause to go in the opposite direction

4. flow

5. speed

6. space between 2 lines or surfaces that meet

7. send out (speech, music, etc.) in all directions, especially by radio or TV

8. the same in size, amount, value, etc.

Exercise 4. Complete the following sentences and translate them into Russian.

1. … are the frequency, intensity, direction of travel …

2. … from the above equation to have a long wavelength …

3. … varies with the amount of interference that is present.

4. One-half of the electrical energy …

5. … were reversed, the direction of travel …

6. … is known as the wave front.

7. … abbreviated kHz, or in megahertz …

Exercise 5. Put the words in the correct order.

1. Free space, exists, electrical energy, in the form of, that, electromagnetic waves, has escaped, into.

2. Travel, the velocity, radio waves, of, light, with.

3. An alternating current, vary, with the frequency, the radio waves, of the current, produced by, in intensity.

4. Corresponds, wave, to, a short wavelength, high, frequency, a.

5. The direction, of the wave, lines of flux, polarisation, is called, the direction, the electrostatic lines, of.

Exercise 6. Put as many questions as possible to the last sentence of the second paragraph.

Exercise 7. Translate the first three paragraphs of the text.

Exercise 8. Find in the text the sentences with Participles in the function of an attribute. Translate the sentences into Russian.

Exercise 9. Translate the following sentences into Russian. Pay attention to the functions of the Participles.

1. Frequencies ranging from 300 to 3000 kHz are referred to as medium radio frequencies.

2. The velocity of light has a special significance in the Universe, its value being 300 mln metres per second in a vacuum.

3. Having been tested under unfavourable conditions, the machine was successfully put into operation.

4. The device demonstrated is the simplest type.

5. The current induced in the coil of the electromagnet will also oscillate at the frequency of the original sound.

6. Having finished the research, the scientists made a thorough analysis of the data obtained.

7. Electromagnetic waves of frequencies called radar frequencies provide a method of seeing in the dark or in fog.

8. The laboratory just referred to was provided with the most modern measuring devices.

9. An aircraft travelling at less than the speed of sound creates pressure waves ahead of itself.

Exercise 10. Define whether the following statements are true or false and correct the false statements.

1. The radio waves produced by a direct current will vary in intensity with the frequency of the current.

2. The frequency is expressed in kilohertz or megahertz.

3. Under the most favourable conditions it is possible to obtain intelligible signals from waves having a strength as low as 0.1 mv per cm.

4. In rural locations a field strength of 5000 to 30,000 mv per meter is needed to insure good reception at all times.

5. A wave always travels in a direction at right angles to the wave front.

6. The wave is vertically polarized when the electrostatic flux lines are vertical.

7. The strength of a radio wave is expressed in microvolts stress per meter.

Exercise 11. Annotate the text.

Text B.

Exercise 1. Read and entitle the text.

If a stretched wire or string is plucked, it will vibrate in regular manner at a definite frequency which will depend on the radius (r) and density (ρ) of the string, its tension (T), and its unsupported length (l). In fact the frequency (f) is given by formula:

The energy of the vibrating string will cause the surrounding molecules of air to vibrate in a similar manner, so that a sound wave will be transmitted in all directions through the air with a frequency identical to that of the vibrating string. This wave, when it impinges on the ear-drum, will cause a vibration to pass through the bone and nerves of the inner ear to the brain.

The ear, which is a very delicate instrument, is capable of differentiating between frequencies in the whole range of audibility, and the brain will register a certain note. The range of human audibility is from about 20 hertz to about 20 000 hertz, and any periodic vibration of matter, in any form, within this frequency range will cause an audible sound.

All sounds have three characteristics: pitch, loudness and quality (or timbre). The pitch of a sound depends only on its frequency.

The loudness of a sound depends on the amount of energy contained by the wave by which it is transmitted and is related directly to its amplitude.

The quality or timbre of a sound depends on the number and strength of the overtones that are produced together with the basic frequency.

The transmission of energy in the form of sound waves has very much in common with the transmission of energy by electromagnetic waves, but there are three important differences. Firstly, sound waves cannot be radiated through empty space — they require matter for their propagation (solid, liquid, or gaseous). Secondly, they travel much more slowly than electromagnetic waves. The speed of sound depends on the material through which it is passing; it is faster in solids than in liquids, and faster in liquids than in gases. The velocity of sound in air is about 331 metres per second which is slower than the speed of fast (supersonic) aeroplanes.

The third difference between sound and electromagnetic waves is that the former are longitudinal waves, whereas the latter are transverse waves. In a transverse wave the undulations are at right angles to the direction of the wave. In a longitudinal wave, however, the movement of the particles is in the same direction as the wave, not across it as with a transverse wave.

(Source: Kabo P. Fomitchova S. Popular science reader. Moscow. 1983. pp. 37-39)

Exercise 2. Make up a plan of the text.

Exercise 3. Retell the text.

Exercise 4. Speak on the topic: “The differences between sound and electromagnetic waves”.

UNIT 5

Topic: Major Steps of Electronics History

Text A. Electronics

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

encompass – содержать, заключать (в себе)

device – прибор, устройство, схема

integrated circuit – интегральная схема, микросхема

optical fibre – оптическое волокно, световод

array – целый ряд, большое количество, масса, множество

consumer – широкого потребления (о товарах)

cellular telephone – сотовый телефон

sophisticated – сложный

impact – воздействие, влияние

pervasive – распространяющийся, проникающий

digital – цифровой, дискретный

intermingle – смешивать, перемешивать

regenerate – восстанавливать

attenuate – истощать, ослаблять

intricate – сложный, запутанный

Exercise 2. Repeat and translate into Russian the following words.

a) with one stress or the stress on the first syllable

circuit, fibre, impact, access, deal, utilize, range, constitute, cellular, intricate, physics, technical, science, integrate, volume, digital

b) with the stress on the second syllable

array, performance, apply, encompass, convert, facilitate, experience, attenuate, regenerate, exceptional, consumer, sophisticated, pervasive, apparent, effect, electron

c) with two or more stresses

intermingle, manufacture, optical fibre, integrated circuit, scientific, fundamental, mathematics, engineering, radiotelephone, high-performance

Exercise 3. Study the following words and choose

a) nouns

1. apply, application, applied, applicable, applicant, appliance;

2. significance, significant, significative, signify, signification;

3. electronic, electronics, electronically, electronicize, electron;

4. breadth, broad, broaden, broadly.

b) adjectives

1. physics, physicist, physical, physic;

2. facility, facilitate, facilitation, facile;

3) science, scientist, scientific, scientifically;

4) except, exception, excepting, exceptive, exceptional.

ELECTRONICS

Electronics is a branch of physics that deals with the emission, behaviour, and effects of electrons (as in electron tubes and transistors) and with electronic devices.

Electronics encompasses an exceptionally broad range of technology. The term originally was applied to the study of electron behaviour and movement. It came to be used in its broader sense with advances in knowledge about the fundamental nature of electrons and about the way in which the motion of these particles could be utilized. Today many scientific and technical disciplines—including physics, chemistry, materials science, mathematics, and electrical and electronic engineering—deal with different aspects of electronics.

Research in these fields has led to the development of such key devices as transistors, integrated circuits, lasers, and optical fibres. These in turn have made it possible to manufacture a wide array of electronic consumer, industrial, and military products. These products range from cellular radiotelephone systems and videocassette recorders to high-performance supercomputers and sophisticated weapons systems. By the mid-1980s the electronics industry was the largest manufacturing industry in the United States. Japan and the industrialized nations of Western Europe also had flourishing electronics industries, while various developing countries— including South Korea, Taiwan, and Israel—experienced significant advances as well.

The impact of electronics on modern life has been pervasive. It can be said that the world is in the midst of an electronic revolution at least as significant as the industrial revolution of the 19th century. Evidence of this is apparent everywhere.

Electronics is essential, for example, in telecommunications. An ever-increasing volume of information is transmitted in digital form. Digital techniques, in which signals are converted into groups of pulses, allow the intermingling of voice, television, and computer signals into one very rapid series of pulses on a single channel that can be separated at the receiving end and reconstituted into the signals originally sent. Because the digital pulses can be regenerated perfectly after they become attenuated with distance, no noise or other degradation is apparent at the receiving end.

Electronic controls for industrial machines and processes have made possible dramatic improvements in productivity and quality. Computer-aided design tools facilitate the designing of parts that have complex shapes, such as aircraft wings, or intricate structures, such as integrated circuits. The production of designs of this sort is done by computer-controlled machines that receive instructions directly from the design tools.

Access to knowledge has been made far easier by computerized indexes of scientific and technical journals, which are accessible from centralized services over telephone lines. These central databases are being supplemented by new techniques derived from digital audio and video disc technology, which provide locally, and at low cost, access to vast amounts of information in text and graphic form.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words.

Circuit, fibre, impact, deal, utilize, range, cellular, volume, performance, convert, facilitate, attenuate, pervasive, apparent, manufacture.

Exercise 2. Find English equivalents of the following words in the text.

Электронная лампа, необычайно широкая область, первоначально, поведение электрона, интегральная схема, оптическое волокно, в свою очередь, товары широкого потребления, современные системы вооружения, по крайней мере, цифровая технология, резкое улучшение, средства автоматизированного проектирования, сложные структуры, доступ к знаниям, центральные базы данных.

Exercise 3. Match the words with their definitions.

word

definition

1. circuit

2. impact

3. access

4. apply

5. manufacture

6. sophisticated

7. apparent

8. range

9. convert

1. strong impression or effect

2. change from one form into another

3. closed path for an electric current

4. make practical use

5. vary between limits

6. clearly seen or understood

7. complex, with the latest improvement and refinements

8. produce goods on a large scale by machinery

9. right, opportunity or means of reaching, using or approaching

Exercise 4. Arrange the words of the two groups in pairs.

1. with similar meaning

1. encompass

2. intricate

3. exceptional

4. attenuate

5. intermingle

6. constitute

7. facilitate

8. deal with

9. rapid

1. relation

2. weaken

3. complicated

4. fast

5. out of ordinary

6. make easy

7. establish

8. mix together

9. surround

b) with contrary meaning

1. broad

2. advance

3. motion

4. different

5. consumer

6. facilitate

7. attenuate

8. essential

9. complex

1. regress

2. strengthen

3. producer

4. narrow

5. complicate

6. unimportant

7. the same

8. simple

9. rest

Exercise 5. Complete the following sentences choosing the most suitable variant.

1. Manufacturing of many electronic products became possible thanks to the invention of

a) high-performance supercomputers;

b) transistors, ICs and other electronic devices;

c) sophisticated weapons systems.

2. In digital techniques signals are changed into

a) groups of pulses;

b) voice;

c) electric current.

3. There is no noise at the receiving end

1. because of the perfect regeneration of the digital pulses;

b) because the digital pulses become attenuated with distance;

c) because the digital pulses can be separated at the receiving end.

4. It became easier to design complex shapes and structures with the help of

1. industrial machines;

b) machine-tools;

c) computer-aided design tools.

5. Obtaining information was facilitated by

1. telephone lines;

b) scientific and technical journals available;

c) computerization.

Exercise 6. Translate the third and the fifth paragraphs of the text.

Exercise 7. True or false:

1.. Electronics studies electronic phenomena, devices and systems.

2.. Nowadays electronics is out of relation to chemistry.

3. In 1980 the US electronics industry was underdeveloped.

4. The electronic revolution is less important than the industrial revolution of the 19^th century.

5. In digital techniques signals are mixed on a single channel.

6. Productivity and quality in industry were greatly improved thanks to electronics.

7. At present the only opportunity of getting information is over telephone lines.

Exercise 8. Answer the following questions

1. What is electronics?

2. Why did the term electronics acquire a wider meaning?

3. What branches of science are connected with electronics?

4. What devices made it possible to produce not only videocassette recorders but also high-performance supercomputers?

5. In 1980s electronics industries weren't developed at all in the industrialized European countries, were they?

6. In what field of engineering is electronics of great importance?

7. In what form is most of information sent at present?

8. Does it take much time to obtain information now?

Exercise 9. Speak about the significance of electronics

Text B.

Exercise 1. Read and translate the following text and entitle it.

The working principles of electronics can be demonstrated by tracing the history of radio tubes and photoelectric cells. The history began in 1883, when Thomas Edison found that the heated filament in his incandescent lamp gave off material that blackened the inside of the bulb. This was called the Edison effect, and it led to the development of the modern radio tube. In the Edison effect, also called thermionic emission, heat supplies some electrons in the filament with at least the minimal energy to overcome the attractive forces holding them in the structure of the metal. This discharge of electrons is widely used as a source of electrons in conventional electron tubes—for example, in television picture tubes.

In 1887 Heinrich Hertz, while trying to prove the existence of radio waves, discovered the photoelectric effect. If polished metal is given a negative charge and then is flooded with ultraviolet radiation, it steadily loses the charge. Some chemical elements such as cesium and selenium are sensitive to visible light. This discovery led to photoelectric cells.

The development of the radio tube began in 1904, when John A. Fleming of England produced the Fleming valve, which today is called a diode, meaning "two electrodes." He started by heating a filament (also called a cathode) in a vacuum tube with "A-circuit current." The heat drove electrons out of the filament and into surrounding space.

If nothing more happened, the first electrons to escape would soon have formed a negative space charge that would have kept others from being driven out because like charges repel. Fleming avoided this by placing a plate in the tube and connecting the plate and filament through an outside B circuit. The electrons driven from the filament then crossed the tube to the plate and followed the circuit back to the filament.

Fleming next placed a battery in the B circuit. The battery was used to supply electrons—that is, negative charges—to the filament, or cathode, and draw them from the plate, or anode, leaving a positive charge. Electrical heating drove electrons steadily from the filament and sent a strong current through the B, or plate, circuit. The strength of the current depends partly upon the heat and partly upon the voltage from the battery.

This device could be used as a radio detector. The changing voltages created by radio signals in an antenna circuit are placed on the filament and plate. The changes produce corresponding changes in the strength of the plate current, which is used to reproduce the signal in the receiving apparatus.

In 1906 the American inventor Lee De Forest transformed the diode into a device that he called an audion, the modern name of which is triode. He did this by inserting a grid of fine wire mesh between the filament and the plate.

If variable voltages from an antenna circuit are placed on the filament and the grid, they cause variations in the flow of electrons to the plate. Moreover, the variations in current are much stronger than those caused by the voltage of the incoming signal acting alone. Thus the triode amplifies, or strengthens, the signal.

Because the tube uses free electrons only and has no mechanical moving parts, it responds within a few microseconds, or millionths of a second, to any change placed upon it. It can be made sensitive to changes of less than a millionth of a volt. Resulting changes in the plate current can be amplified by passing the signal through more tubes.

The vacuum tube became the basis of radio, television, and computers, the latter first developed at the end of World War II in 1944 and 1945. The invention of the transistor in 1947 initiated a radical reduction in the size of electronic circuits and in their power requirements. The later development of the integrated circuit set into motion the continuing miniaturization of all electronic devices, which has at the same time greatly increased their speed and computing power.

Notes

radio tube - электронная лампа

filament - нить накала

incandescent lamp-лампа накаливания

photoelectric cell – фотодиод

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Answer the following questions on the contents of the text.

1. What discovery led to the modern radio tube?

2. When was the photoelectric effect discovered?

3. What does the Fleming valve consist of?

4. What does a triode differ from a diode?

5. When did the first computers appear?

Exercise 3. Read the text again and be ready to speak on the following problems:

1. Thomas Edison's discovery.

2. The development of radio tube.

3. Lee De Forest's contribution to the development of electronics.

4. Major steps of electronics history.

Exercise 4. Speak on the topic: “Major steps of electronic history”.

UNIT 6

Topic: Integrated Circuits

Text A. Functions of ICs

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

integrated circuit – интегральная схема

versatile – разносторонний, многосторонний, универсальный

circuitry – схема

amplification – усиление

magnify – увеличивать

oscillator – излучатель, осциллятор, генератор

beat – бой, биение

pendulum – маятник

external – внешний

oscillation – колебание, качание, вибрация

array – множество

fidelity – точность воспроизведения, (качество воспроизведения)

appliances – приборы, бытовые электроприборы

measurement – измерение

test pattern – испытываемый образец

virtually – фактически, в сущности

switch – переключать, коммутировать

network – сеть

supplement – дополнять, пополнять

fiber – волокно, нить

Exercise 2. Repeat and translate into Russian the following words:

a) with one stress or stress on the first syllable:

beat, circuit, fiber, gripper, pendulum, wave, actual, vital, carry, range, tie, tune;

b) with the stress on the second syllable:

response, internal, invaluable, control, convert, determine, manufacture, prevent, transmit, efficiently, exactly;

c) with two or more stresses:

interference, oscillator, sophisticated, versatile, voluminous, amplify, magnify.

Functions of ICs

Integrated circuits are extremely versatile because a single basic design can be made to perform hundreds of different functions, depending on the wiring of the circuits and the electronic programs or instructions that are fed into them. Most ICs perform calculations or logic manipulations in devices ranging from hand-held calculators to ultrafast supercomputers that can perform billions of calculations per second.

There are many other functions, however, that can be done with electronic circuitry. In radio and television receivers a primary function of circuits is the amplification of weak signals received by the antenna. In amplification a small signal is magnified to a large signal that is used to drive other circuits such as the speakers of a radio.

In many cases this amplification is performed with the help of oscillator circuits. Such circuits have a natural period or cycle of electrical current, similar to the natural beat of a pendulum. When driven by external signals of the same period, such as the transmission from a particular radio channel, the oscillator circuit increases its amplitude of oscillation.

To tune out other radio or television stations also received by a single antenna, filter circuits are frequently used. Such filters strongly reduce the signals at all but a single frequency, preventing interference among channels in a receiver.

These and other basic circuit types are used in a vast array of electronic devices. Consumer electronics, a field that was first developed in the 19th century with the invention of the phonograph, now includes radios, television sets, high-fidelity stereo systems, tape recorders, calculators, video

games, and personal computers. Most of these devices contain one or more integrated circuits. Electronic controls have also been added to many electrical appliances such as dishwashers, washing machines, ovens, and food processors.

In industry and trade the computer, made up of from one to several thousand integrated circuits, has become an invaluable tool, controlling industrial operations and keeping track of voluminous business records.

Scientists use electronic computers to perform extremely complex calculations such as determining exactly the course of distant space probes; the probes themselves are packed with electronic instruments and communications equipment. Electronic instruments are used on Earth for scientific measurements and in the electronics industry itself to test equipment as it is manufactured. The oscilloscope, for example, is used to diagnose problems in electronic circuits, through a comparison of expected test patterns with actual results.

In the field of medicine electronic diagnostic instruments have given physicians a much clearer view of the human body than ever before.

Virtually all modern communications rely on electronics. Electronic circuits switch telephone calls both on Earth and in communications satellites. Satellite electronics systems amplify and retransmit television and radio communications. Computers are tied together by electronic networks.

Conventional electronics is now supplemented in communications by optoelectronics, the use of laser light carried by optical fibers to transmit information at high speed. Laser pulses are modulated by electronic signals, and the light at the other end of the fiber many kilometers away is converted back into electronic signals by photo detectors.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Ultrafast, electronic circuitry, primary function, weak signals, similar, pendulum, amplitude of oscillation, tune out, interference, manufacture, actual results, amplify, fidelity.

Exercise 2. Give English equivalents of the following words and word-combinations.

Прибор, амплитуда, вычисление, потребитель, печь, записи, сборка, курс, космический зонд, оборудование, измерения, образец, магнитное поле, заболевание, челнок, ракета.

Exercise 3. Match the words with their definitions.

words

definition

1. circuit

2. beat

3. fiber

4. fidelity

5. oscillator

6. pendulum

7. response

8. complex

9. internal

10)voluminous

1. hit repeatedly;

2. one of the slender threads of which many animal and vegetable growths are formed, e.g. cotton, wood, nerves, muscles;

3. clothed path for an electrical current;

4. device for producing electric oscillations;

5. accuracy, exactness;

6. answer, reaction;

7. difficult to understand or explain;

8. weighted rod hung from a fixed point so that it swings freely, especially one to regulate the movement of a clock;

9. great in quantity; occupying much space;

10. of or in the inside;

Exercise 4. Arrange the words of the two groups in pairs.

1. with similar meaning

1. response

2. voluminous

3. to supplement

4. to amplify

5. to control

6. fast

7. to magnify

8. complex

9. to manufacture

10) to determine

11) vast

12) versatile

13) to highlight

1. to draw attention to;

2. sophisticated;

3. to strengthen;

4. to direct;

5. to define;

6. to increase;

7. answer;

8. to produce;

9. to add;

10. rapid;

11. extensive;

12. many-sided;

13. huge;

2. with contrary meaning

1. fast

2. internal

3. invaluable

4. sophisticated

5. vital

6. voluminous

7. to amplify

8. to assemble

9. to magnify

10) to pack

11) to prevent

12) to tie

13) exactly

14) efficient

1. to weaken;

2. simple;

3. slow;

4. to take to pieces;

5. to reduce;

6. to unpack;

7. to promote;

8. to untie;

9. approximately;

10. external;

11. valuable;

12. small;

13. unimportant;

14. inefficient;

Exercise 5. Study the following words and choose:

a) nouns

1. a) actual; b) act; c) actuality; d) actualize

2. a) amplify; b) amplification; c) amplifier; d)amplified

3. a) carry; b) carrier; c)carriage; d)carried

4. a) guide; b) guidance; c)guided; d)guiding

5. a) vast; b) vastness; c) vastly; d) vastitude

6. a) vital; b) vitalize; c) vitality; d)vitalization

7. a) volume; b) voluminous; c) volumetric; d) voluminosity

b) adjectives

1. a) axe; b) axial; c) axle; d) axled

2. a) pendulum; b) pendant; c) pendulous; d) pendulate

3. a) control; b) controller; c) controllable; d)controllability

4. a) determine; b) determinate; c) determinable; d) determination.

5. a) magnify; b) magnificence; c) magnificent; d) magnification.

6. a) prevent; b) preventive; c) prevention; d) preventor

7. a) transmitter; b) transmit; c) transmissible; d) transmitting

8. a) tune; b) tuneful; c) tuned d) tuner

Exercise 6. Form the necessary part of speech and fill in the gaps.

1. Integrated circuits are extremely ... because they perform hundreds of different functions (versatility).

1. Most ICs perform ... or logic manipulations in devices (calculate).

3. In radio and television ... a primary function of circuits is the amplification of weak signals (receive).

4. ... other radio or television stations, filter circuits are frequently used (to tune out).

5. In industry the computer has become an invaluable tool ... industrial operations (control).

6. Scientists use electronic computers ... extremely complex calculations (performance).

7. Complex circuits are ... when used in space such as on board space shuttles (vitality).

Exercise 7. Translate the second, the third and the fourth paragraphs of the text.

Exercise 8. Answer the following questions.

1. Why are integrated circuits extremely versatile?

2. What functions do ICs perform?

3. What circuits have a natural period similar to the natural beat of a pendulum?

4. What do filter circuits do?

5. What does consumer electronic include?

6. What functions does electronic computer perform in industry, trade and science?

7. How are electronic circuits used in modern communications?

Exercise 9. Define whether the following statements are true or false.

1. In radio or television receivers a secondary function of circuits is the amplification of weak signals received by the antenna.

2. In amplification a large signal is magnified to a small signal.

3. Amplification isn't performed with the help of oscillator circuits.

4. Filter circuits are frequently used to tune out other radio or television stations.

5. The computer controls industrial operations and keeps track of voluminous business records.

6. Electronic instrument diagnosing problems in electronic circuits is the amplifier.

7. Electronic circuits switch telephone calls both on Earth and in communications satellites.

Exercise 10. Complete the following sentences choosing the most suitable variant.

1. Integrated circuits are extremely …

a) simple b) versatile c)large

2. Amplification of weak signals is performed with the help of....

a) scanner circuits b) oscillator circuits c) filter circuits

3. Filter circuits are used ....

a) to increase the signals b) to tune out radio or television stations c) o interfere in the channels in a recover

4. Consumer electronics was first developed....

a) in the 20^th century b) in the 19^th century c) in the 21^st century

5. Many electrical appliances have got....

a) displays b) scanners c) electronic controls

6) The device used to diagnose problems in electronic circuits is called

a) calculator b) oscilloscope c) laser

7) Television and radio communications are amplified and
retransmitted by ....

a) satellite electronics systems b) navigation system c) television system

8. Laser light is carried by ....

a) optical fibers b) wires c) sound signals

Exercise 11. Develop the following ideas. Use the words provided in the brackets.

1. The use of ICs in radio and television receivers (amplification, weak signal, to magnify to a large signal, oscillator circuits, the natural beat of a pendulum, a natural period of electric current, to tune radio or TV stations, filter circuits).

2. The use of ICs in consumer electronics (vast array of electronic devices, phonograph, radio and television sets, high-fidelity stereo systems, tape recorders, personal computers, contain, electrical appliances, to add, washing machines ovens, food processors.

3. The use ICs in science (to perform complex calculations, determining the course of distant space probes, to be packed with, electronic instruments and communications equipment, measurements, to test equipment, oscilloscope, to diagnose problems in electronic circuits, test patterns, actual results).

Text B.

Exercise 1. Read and entitle the text.

Despite the importance of these other types of electronic devices, semiconductor-based circuits are the essential features of modern electronic equipment. These circuits are not made up of individual, separated components as was once the case. Instead, thousands of tiny circuits are embedded in a single complex piece of silicon and other materials called an integrated circuit (IC).

The manufacture of integrated circuits begins with a simple circular wafer of silicon a few inches across. Designers have produced drawings of exactly where each element in the finished circuits is to go. Usually these diagrams are themselves made with the help of computers. Photographs of the diagrams are then reduced in size many times to produce a photolithographic mask. The wafers are first coated with a material called a photoresist that undergoes a chemical change when exposed to light. Light shone through the mask onto the photoresist creates the same pattern on the wafer as that on the mask. Solvents then etch away the parts of the resist exposed to light, leaving the other parts intact.

After this another layer of material—for example, silicon doped with some impurities—is laid down on top of the wafer, and another pattern is etched in by the same technique. The result of several such operations is a multilayered circuit, with thousands of tiny transistors, resistors, and conductors created in the wafer.

The wafer is then broken apart along prestressed lines into dozens of identical square or rectangular chips—the finished integrated circuits.

Individual chips are mounted on carriers with several dozen connector leads emerging from them. These, in turn, are soldered together onto printed circuit boards that may contain many dozens of chips.

By the mid-1980s integrated circuits made with the most advanced technology could carry as many as a million individual transistors, each only a few microns on a side. (A micron is a thousandth of a millimeter, or 0.00004 inch.) Many electrical engineers and scientists believe that the ultimate limits of size in these circuits might soon be reached.

It was expected that the circuit elements would become too small and contain too few individual atoms to be manufactured reliably. To continue the reduction in size and cost of microcircuits, new principles of operation may be required, perhaps involving specially designed organic molecules.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Put 5 questions to the text.

Exercise 3. Annotate the text.

Exercise 4. Speak on the following topic: “Wide use of integrated circuits in the our life”.

UNIT 7

Topic: Semiconductors

Text A. What Semiconductors are

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

semiconductor – полупроводник

conduct – проводить

motion – движение

insulator – диэлектрик, изолятор

displacement – смещение, перемещение

charge – заряд

exhibit – проявлять, обнаруживать

increase – возрастание, увеличение

silicon – кремний

interfere with – мешать

resistance – сопротивление

loosely – свободно

current carrier – носитель тока

release – освобождать, отпускать

impurity – примесь

arsenic – мышьяк

dissolve – растворяться

trace – след, незначительное количество

deficit conduction – недостаточная проводимость

equilibrium – равновесие

unequal – неравный

interface – граница, контактная поверхность

barrier layer – барьер, запирающий слой

direction – направление

Exercise 2. Translate the following groups of words of the same root into Russian.

1. conduct-conductor-conduction-conductive

2. insulate-insulator-insulation-insulating

3. vary-variety-variable-variability

4. resist-resistance-resistant-resistivity

5. apply-appliance-applicable-application

6. reduce-reduction-reducible-reduced

7. remove-removal-removable-removability

Semiconductors

A review of the mechanism for conducting electricity through various kinds of matter shows that in metals conduction takes place through the motion of electrons, and that in insulators there is no conduction but only a slight displacement of the charges within the atoms themselves. There is still another kind of matter in which conduction takes place by electrons just as in metals, but, contrary to the behaviour of metals, a substance of this kind exhibits an increase of resistance as the temperature falls. Such a substance is referred to as a semiconductor, and at the absolute zero it would be the insulator. Among the examples of semiconductors the most important at present seem to be silicon and germanium.

The variation of resistance with the temperature is accounted for as follows. In a metal only a very few electrons are free to move upon application of a potential difference. The temperature of the metal being lowered, the thermal vibration of its atoms is reduced; as a result the atoms interfere less with the motion of the electrons , and consequently the resistance is lowered. Those electrons free to move in a metal are in semiconductors bound loosely to the atoms. At absolute zero a semiconductor has no current carriers. The temperature being raised, more and more of the loosely bound electrons are released by the thermal energy and conduction is improved, which means that the resistance is lowered as the temperature rises.

The current carriers in a semiconductor may be supplied by an impurity. For example, an arsenic impurity in silicon supplies one loosely bound excess electron for each atom of arsenic dissolved, and hence conduction is due to a transfer of excess electrons; such a semiconductor is said to be of n-type, because of the carriers being negative. In contrast a trace of boron in silicon removes one electron for each atom of boron dissolved, and the “hole” left in the electronic structure of a silicon atom provides a type of conduction, called hole or deficit conduction, by transfer from atom to atom of electrons into available holes. A semiconductor in which the conduction is due to holes is said to be of p-type, because of the carriers acting like positive charges, for the “hole” travels in a direction opposite to that of the electrons filling it.

The importance of semiconductors, at least in present application, arises from their behaviour when in contact with a metal. When the two substances are placed in contact, free electrons in the metal and those in the semiconductor come into equilibrium. Their numbers being unequal, and the force that bind them being unequal too, there is a transfer of electrons, which continues until the charge accumulated is large enough to repel a further transfer of electrons. The accumulation of charge at the interface acts as barrier layer, so-called due to its interfering with the passage of current.

The barrier at the interface between conductor and semiconductor is decreased when potential is applied in one direction and is increased when potential is applied in the opposite direction. Hence, the current will rise sharply with increase of potential in one direction, called the “forward” direction, but will remain small with increase of potential in the other direction.

(Source: Briskina K. Zavadskaja M. English for technical students. Kiev 1977. pp. 79-80)

Post- text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Motion, displacement, matter, behaviour, substance, exhibit, increase, refer to, insulator, potential difference, lower, consequently, supply, carrier.

Exercise 2. Give English equivalents of the following words and word-combinations.

Проводимость, диэлектрик, изменение сопротивления, мешать, улучшаться, примесь, положительный заряд, прийти в равновесие, неравный, контактная поверхность, запирающий слой, резко возрастать.

Exercise 3. Match the words with their definitions:

word

definition

1. electricity

2. review

3. charge

4. conduct

5. variable

6. lower

7. raise

8. unequal

1. allow (heat, electric current) to pass along or through;

2. make or become less high;

3. not equal;

4. consider or examine again;

5. quantity of energy (to be) contained in an electrical battery, etc.

6. supply of electric current;

7. cause to rise;

8. changeable;

Exercise 4. Complete the following sentences and translate them.

1. … is referred to as a semiconductor, and at the absolute zero …

2. As a result the atoms interfere with less …

3. … may be supplied by an impurity

4. Such a semiconductor said to be of n-type because …

5. … is due to holes is said to be of p-type.

6. … acts as barrier layer, so-called due to its …

7. … is decreased when potential is applied in one direction and is increased when …

Exercise 5. Put as many questions as possible to first sentence of the third paragraph.

Exercise 6. Translate the third and the fourth paragraphs of the text.

Exercise 7. Define whether the following statements are true or false.

1. Semiconductors exhibit a decrease of resistance as the temperature falls.

2. When the temperature of a metal is lowered, the resistance is also lowered.

3. At absolute zero a semiconductor has no current carriers.

4. An arsenic impurity in silicon supplies three loosely bound excess electrons for each atom of arsenic dissolved.

5. A trace of boron in silicon adds one electron to each atom of boron dissolved.

6. In p-type semiconductors conduction is due to holes.

7. A semiconductor in which the conduction is due to holes is said to be of n-type.

8) When the two substances are placed in contact, free electrons in the metal and those in the semiconductor come into equilibrium.

Exercise 8. Answer the questions.

1. What substance is called a semiconductor?

2. Does a semiconductor have any current carriers at absolute zero?

3. When is conduction improved in semiconductors?

4. What can you say of n-type and p-type semiconductors?

5. How does the accumulation of charge at the interface between conductor and semiconductor act?

6. In what case is the barrier at the interface between conductor and semiconductor decreased?

Exercise 9. Describe:

1. how conduction occurs in conductors and semiconductors;

2. the variation of resistance with temperature;

3. the importance of semiconductors and their application.

Text B.

Exercise 1. Read, translate the following text and entitle it.

A semiconductor is a substance that conducts electricity with the help of electrons, but less effectively than metals do, yet much better then insulators.

Semiconductors are all minerals; many chemical and organic compounds are semiconductors too. The conductivity of minerals and crystals increases with heating and falls with cooling. Germanium and silicon are most widely used.

As a result, many types of radio equipment now employ semiconductors instead of tubes. In comparison with electron tubes, semiconductor devices have the following advantages:

1) light weight and small sized;

2) no filaments (hence, no power consumption on heating them);

3) longer life;

4) greater mechanical strength;

5) high efficiency of semiconductor circuits, since the energy loss in semiconductors is very low;

6) very low voltages of power supplies.

Semiconductor device, however, have certain disadvantages, which are as follows:

1) considerable difference in parameters and characteristics of individual devices of the same type;

2) great temperature dependence of properties of the devices;

3) semiconductors age rather rapidly, i.e. the properties of the devices vary with time;

4) higher level of noise as compared to electron valves;

5) low frequency limit;

6) the input resistance of transistors is much lower than that of triode tubes.

It should be noted that these disadvantages of semiconductor devices are to a certain extent avoidable.

Semiconductors play an important part in very many fields of industry and engineering. Semiconductors are used for transforming light and heat energy into electrical energy. Besides, semiconductors are used for reproduction of sounds, for transmission of signals, automatic control, for switching on engines.

Semiconductors with foreign impurities are called extrinsic semiconductors. Sometimes the impurity material has an excess of electrons in its atoms. It donates electrons to the conduction band. The electrical charge in the conduction band is negative. That’s why such a crystal is called n-typed semiconductor. Sometimes the impurity material has a deficiency of electrons in its atoms. The acceptor levels are introduced near the valence band.

The electrons from the valence band move into the missing places. The holes are formed. They have the effective positive charges. That’s why such a crystal is called a p-typed semiconductors.

(Source: Златніков В. Г. Практичний курс з вивчення іноземної мови. Київ, 2006. стр 142)

Exercise 2. Put 5 questions to the text.

Exercise 3. Which of the following statements best expresses the main idea of the text.

1. You find semiconductors at the heart of microprocessor chips.

2. Silicon is the heart of any electronic or computer device.

1. Silicon has a unique property in its electron structure and this allows to form nice crystals.

2. A pure silicon crystal is nearly an insulator - very little electricity will flow through it.

Exercise 4. Retell the text.

Exercise 5. Speak on the following topic: “The use of semiconductors nowadays.”

UNIT 8

Topic: Laser

Text A. What is Laser?

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

invade – вторгаться

weapon – оружие

sword of heat – огненный меч

amplification – усиление

stimulate – возбуждать, индуцировать

beam – луч

vaporize – испарять(ся)

heat-resistant – теплостойкий

unamenable – неподдающийся

lead – свинец

installation – установка, сборка

fuel – топливо

disintegrate – распадаться на составные части

capacity – мощность

encode – кодировать

solar – солнечный

Exercise 2. Study the following words and choose

a) nouns

1. reality, real, realistic, realize.

2. intense, intensity, intensive, intensification

3. resistant, resist, resistance, resistive

4. developing, development, developed, develop

5. provide, providing, provision, provided

b) English equivalents

1. устанавливать - installment, installation, install

2. различие, разница - differ, difference, different

3. распадаться - disintegrator, disintegration, disintegrate

4. применимый - application, applicable, apply

1. укреплять - strong, strength, strengthen

2. эффективно - efficient, efficiency, efficiently

3. усилитель-amplification, amplifier, amplify

4. связь - communicate, communicative, communication

5. передавать-transmission, transmitter, transmit

LASER

In the "War of Worlds" written before the turn of the century H. Wells told a fantastic story of how Martians almost invaded our Earth. Their weapon was a mysterious "sword of heat". Today Wells' sword of heat has come to reality in the laser. The name stands for light amplification by stimulated emission of radiation.

Laser, one of the most sophisticated inventions of man, produces an intensive beam of light of a very pure single colour. It represents the fulfilment of one of the mankind's oldest dreams of technology to provide a light beam intensive enough to vaporize the hardest and most heat-resistant materials. It can indeed make lead run like water, or, when focused, it can vaporize any substance on earth. There is no material unamenable to laser treatment and laser will have become one of the main technological tools.

The applications of laser in industry and science are so many and so varied as to suggest magic¹. Scientists in many countries are working at a very interesting problem: combining the two big technological discoveries of the second half of the 20-th century - laser and thermonuclear reaction - to produce a practically limitless source of energy. Physicists of this country have developed large laser installations to conduct physical experiments in heating thermonuclear fuel with laser beams. There also exists an idea to use laser for solving the problem of controlled thermonuclear reaction. The laser beam must heat the fuel to the required temperature so quickly that the plasma does not have time to disintegrate. According to current estimates, the duration of the pulse has to be approximately a thousand-millionth of a second. The light capacity of this pulse would be dozens of times greater than the capacity of all the world's power plants. To meet such demands in practice scientists and engineers must work hard as it is clear that a lot of difficulties are to be encountered on route².

The laser's most important potential may be its use in communications. The intensity of a laser can be rapidly changed to encode very complex signals. In principle, one laser beam, vibrating a billion times faster than ordinary radio waves, could carry the radio, TV and telephone messages of the world simultaneously. In just a fraction of a second, for example, one laser beam could transmit the entire text of the Encyclopedia Britannica.

Besides, there are projects to use lasers for long distance communication and for transmission of energy to space stations, to the surface of the Moon or to planets in the solar system. Project have also been suggested to place lasers aboard Earth satellites nearer to the Sun in order to transform the solar radiation into laser beams, with this transformed energy subsequently transmitted to the Earth or to other space bodies. These projects have not yet been put into effect³, because of the great technological difficulties to be overcome and therefore the great cost involved. But there is no doubt that in time these projects will be realized and the laser beam will begin operating in other space as well.

Notes

1. as to suggest magic - можно принять за чудо

2. on route - на пути

3. put into effect – осуществлять

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words.

Before the turn of the century, mysterious, sophisticated invention, pure single colour, light beam, thermonuclear reaction, limitless source, conduct physical experiments, solve the problem, disintegrate, duration, approximately, encounter, complex signals, simultaneously, transmit, satellite, solar radiation, overcome.

Exercise 2. Read the text and find English equivalents of the following words and word combinations.

средство, усиление, свет, эмиссия, нагрев, топливо, распад, проводить, теплостойкий, обработка, установка, возбуждать (индуцировать), выполнение, инструмент, продолжительность, менять, оружие, передавать

Exercise 3. Match the words with their definitions.

word

definition

1. heat

2. duration

3. tool

4. weapon

5. sophisticated

6. beam

7. message

8. satellite

9. laser

1. a line of light that shines from an object as a torch or the sun

2. a piece of information or a request that you send to someone or leave for them when you cannot speak to them directly

3. an object such as a gun, a knife, or a missile, which is used to kill or hurt people in fight or a war

4. a narrow beam of concentrated light that is used especially for cutting very hard materials and in surgery

5. made using advanced and complex methods

6. warmth or the quality of being hot

7. the length of time during which something happens or exists

8. an object which has been sent into space in order to collect information

9. any instrument or piece of equipment that you hold in your hands in order to help you to do a particular kind of work

Exercise 4. Arrange the words of the two groups in pairs.

1. with similar meaning

1. rapidly

2. sophisticated

3. conduct

4. demand

5. approximately

6. fulfil

7. opportunity

8. application

9. also

1. requirement;

2. almost;

3. carry out;

4. quickly;

5. complex;

6. possibility;

7. realize;

8. as well;

9. use;

2. with contrary meaning

1. further

2. integrate

3. cooling

4. outside

5. powerless

6. controlled

7. limited

8. capable

9. single

1. incapable;

2. powerful;

3. limitless;

4. inside;

5. uncontrolled;

6. heating;

7. disintegrate;

8. nearer;

9. numerous;

Exercise 5. Use the words in brackets to form a word that fits in the space

1) Laser is one of the most sophisticated ... of man. (to invent)

2) Physicists have developed large laser installations to conduct physical experiments in ... thermonuclear fuel with laser beams.(to heat)

3. The ... of a laser can be rapidly changed to encode very complex signals, (to intensify)

4. Laser represents the ... of one of the mankind's oldest dreams of technology .(to fulfil)

5. There are projects to use laser for long distance .... (to communicate)

6. By the end of 2000 laser had become one of the main ... tools, (technology)

7) The laser beam must heat the fuel to the ... temperature. (to require)

8. Lasers may be used for... of energy to space stations. (to transmit)

9. ... in many countries are working at a very interesting problem. (science)

10) There also exists an idea to use laser for solving the problem of controlled thermonuclear. (to react)

Exercise 6. Translate the third and the fifth paragraphs of the text.

Exercise 7. Say whether the following statements are true or false.

1) Laser means "light amplification by stimulated emission of radiation"

2) Laser produces an intensive beam of light

3) In the next few years laser will become one of the main technological tools

4) Martians almost invaded the Earth before the turn of the century

5) Laser and thermonuclear reaction can produce a limited source of energy

6) The laser beam heats the fuel so quickly that the plasma disintegrates

7) There are project to transform lunar radiation into beams

8) The laser beam will begin operate in outer space

Exercise 8. Complete the following sentences choosing the most suitable variant.

1. Laser produces

1. an intensive beam of light

2. hundreds of operations a second

3. integrated circuits

2. The laser's most important potential may be its use ...

1. in telephone

2. in broadcasting

3. in communications

3. Laser has become one of

1. the most complex signals

2. the most heat resistant materials

3. the main technological tools

4. There also exists an idea to use laser for solving the problem of

1. controlled thermonuclear reaction

2. using electricity in devices

3. detecting signals

Exercise 9. Answer the following questions.

1. What does the word "laser" mean?

2. What is laser: is it a device or some phenomenon?

3. Who was the first to write about laser?

4. What can laser do?

5. Where can it be used?

6. What other uses of laser do you know?

7. What is its principle of operation?

8. What light is produced by a laser?

9. What can be done by means of a laser?

10.What prevents putting into effect the projects to use laser more widely in space?

Exercise 10. Speak on the following subjects using the given words.

1. Laser is a very important invention of man (intensive, produce, beam, pure, single, beam, colour).

2. Laser is widely used in science and industry (scientists, problem, works, combine, technological, two, big, discovery).

3. Laser may be used in communications (intensity, change, laser, complex, encode, signal).

4. Lasers will be used for transmission of energy to space stations (long distance communication, the Moon, solar system, surface).

Exercise 11. Speak about the significance of lasers.

Text B.

Exercise 1. Read and translate the text. Entitle it.

One of the most interesting developments in telecommunication is the rapid progress of optical communication where optical fibers are replacing conventional wires and cables. Just as digital technologies greatly improved the telephone system, optical communication promises a considerable increase in capacity, quality, performance and reliability of the global telecommunication network. New technologies such as optical fibers will increase the speed of telecommunication and provide new, specialized information service. Voice, computer data, even video images, will be increasingly integrated into a single digital communication network capable to process and transmit virtually any kind of information.

It is a result of combining two technologies: the laser, first demonstrated in 1960, and the fabrication 10 years later of ultra-thin silicon fibres which can serve as light wave conductors. With the further development of very efficient lasers plus continually improved techniques to produce thin silica of incredible transparency, optical systems can transmit pulses of light as far as 135 kilometers without the need for amplification or regeneration.

At present high-capacity optical transmission systems are being installed between many major US cities at a rapid rate. The system most widely used now operates at 147 megabits (thousand bits) per second and accommodates 6,000 circuits over a single pair of glass fibres (one for each direction of transmission). This system will soon be improved to operate at 1.7 gigabits (thousand million bits) per second and handle 24,000 telephone channels simultaneously.

A revolution in information storage is underway with optical disk technology. The first optical disks appeared in the early 1970-s. They were and are used to record video films, but in a continuous spiral rather than digitally.

The first digital optical disks were produced in 1982 as compact disks for music. They were further developed as a storage medium for computers. The disks are made of plastics coated with aluminum. The information is recorded by using a powerful laser to imprint bubbles on the surface of the disk. A less powerful laser reads back the pictures, sound or information. An optical disk is almost indestructible and can store about 1000 times more information than a plastic disk of the same size.

The latest optical disk development is a system which enables computer users to record their own information on a glass or plastic disk coated with a thin film of tellurium. Such a disk can store 200 megabytes (200 million characters).

Besides, it is reported that an optical equivalent of a transistor has been produced and intensive research on optical electronic computers is underway at a number of US companies as well as in countries around the world.

It is found that optical technology is cost-effective and versatile. It finds new applications every day - from connecting communication equipment or computers within the same building or room to long-distance transcontinental, transoceanic and space communications.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Put 5 questions to the text.

Exercise 3. Retell the text.

Exercise 4. Speak on the following topic: “Lasers and their use”.

UNIT 9

Topic: Telecommunication System

Text A. Telecommunication

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

coaxial – коаксиальный

existence – обмен

filament – нить накала

optical fiber – оптическое волокно

repeater station – ретрансляционная станция

satellite – спутник

spread – распространение

wire transmission – проводная передача

convert – превращать

encode – кодировать, шифровать

supplement – дополнять

tie – связывать

enormously – чрезвычайно

increasingly – всё больше и больше, всё в большей и большей степени

instantly – немедленно

instantaneously – моментально

Exercise 2. Repeat and translate into Russian the following words.

1. with one stress or the stress on the first syllable:

tie, band, bundle, filament, frequency, medium, message, network, satellite, spread, huge, various, carry, dial, supplement, instantly.

2. with the stress on the second syllable:

account, exchange, existence, assume, convert, encode, process, require, transmit, enormously, increasingly

3. with two or more stresses:

coaxial cable, optical fiber, repeater station, wire transmission, instantaneously

Exercise 3. Study the text and try to understand all details.

TELECOMMUNICATION

Communication ties together the parts of a society just as the nervous system ties together the parts of an individual. From earliest times, when the only form of communication was speech, to the present, when electronic signals carry information instantly to practically any point on Earth, communication has been the way people have organized their cooperative activities. In the modern world there are two main types of communications media. One type consists of the mass media—such as television, radio, newspapers, and magazines—in which organizations send messages to a large number of people. The other type consists of direct, point-to-point communications—telephone, telegraph, data transmission, and postal service. Of these, the electronic media (all but the postal service) are termed telecommunications.

Telecommunication first came into existence with the development of the telegraph in the 1830s and 1840s. For the first time, news and information could be transmitted great distances almost instantaneously. The invention of the telephone in 1876 by Alexander Graham Bell fundamentally transformed telecommunications. The telephone system assumed its modern form with the development of dial phoning and its spread during the middle decades of the 20thcentury.

After 1975, however, a new transformation of telecommunications began. The technology used to carry information changed radically. At the same time ordinary telephone and telegraph traffic was enormously supplemented by huge masses of computer data, as millions of computers were tied together into global networks.

In most cases telecommunications systems transmit information by wire, radio, or space satellite. Wire transmission involves sending electrical signals over various types of wire lines such as open wire, multi pair cable, and coaxial cable. These lines can be used to transmit voice frequencies, telegraph messages, computer-processed data, and television programs.

Another somewhat related transmission medium that has come into increasingly wider use, especially in telephone communications, is a type of cable composed of optical fibers. Here electrical signals converted to light signals by a laser-driven transmitter carry both speech and data over bundles of thin glass or plastic filaments.

Radio communications systems transmit electronic signals in relatively narrow frequency bands through the air. They include radio navigation and both amateur and commercial broadcasting. Commercial broadcasting consists of AM, FM, and TV broadcasting for general public use.

Satellite communications allow the exchange of television or telephone signals between widely separated locations by means of microwaves—that is, very short radio waves with wavelengths from 4 inches to 0.4 inch (10 centimeters to 1 centimeter), which correspond to a frequency range of 3 to 30 gigahertz (GHz), or 3 to 30billion cycles per second. Since satellite systems do not require the construction of intermediate relay or repeater stations, as do ground-based microwave systems, they can be put into service much more rapidly.

Modern telecommunications networks thus not only send the traditional voice communications of telephones and the printed messages of telegraphs and telexes, they also carry images—the still images of facsimile machines or the moving images of video—television transmissions used in videoconferences in which the participants can see as well as hear each other. Additionally they carry encoded data ranging from the business accounts of a multinational corporation to medical data relayed for analysis by physicians thousands of miles from a patient.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Computer data, wire lines, multi pair cable, coaxial cable, computer-processed data, commercial broadcasting, satellite communication, ground-based microwave system, additionally

Exercise 2. Find the equivalents of the following words and word-combinations.

Мгновенно передавать информацию, средства массовой информации, посылать сообщения, принимать современный вид, дополнять, огромные массивы компьютерных данных, сеть, коаксиальный кабель, проводная передача, частота, оптоволоконный кабель, пучки, преобразовывать в световые сигналы, полоса частот, позволять обмен, длина волны, ретрансляционная станция, дополнительно.

Exercise 3. Match the words with their definitions:

word

definition

1. filament

2. encode

3. dial

4. supplement

5. tie

6. progress

7. instantly

8. huge

9. satellite

10)cable

1. any manmade object launched from and revolving around the earth

2. a fine wire with a high resistance; it is heated by the passage of an electric current, it is used in electric-light bulbs

3. very great in size, quantity, extent…

4. call by means of a telephone

5. at once

6. a conductor for a high electric current; it consists of several wire twisted together and covered with insulating material such as rubber, plastic, cloth

7. to carry out a progress on data for a particular purpose, may be carried by a person, or by a computer.

8. to convert (a message, document…) from plain text into code

9. make an addition or additions to

10. to make a connection

Exercise 4. Arrange the words of the two groups in pairs

1. with a similar meaning

1. huge

2. various

3. require

4. supplement

5. tie

6. existence

7. carry

8. convert

9. data

10) instantaneously

11) transmit

12) change

13) consist

14) use

15) by means of

1. with the help of;

2. alter;

3. send;

4. enormous;

5. information;

6. different;

7. connect;

8. apply;

9. compose;

10. conduct;

11. immediately;

12. being;

13. addition;

14. demand;

15. transform;

b) with contrary meaning

1. transmit

2. various

3. tie

4. wide

5. thin

6. include

7. allow

8. encode

9. rapidly

1. separate;

2. exclude;

3. receive;

4. slowly;

5. decode;

6. similar;

7. forbid;

8. narrow;

9. thick;

Exercise 5. Translate the 6^th and 7^th paragraphs of the text.

Exercise 6. Read the text and answer the questions.

1) What does communication tie?

2) How many types of communications media are there in the world?

3) Who fundamentally transformed telecommunications?

4) What was ordinary telephone and telegraph traffic enormously supplemented by?

5) What does wire transmission involve?

6) How do electrical signals carry speech and data in optical fibres?

7) Do radio communications systems include amateur broadcasting?

8) What are microwaves?

9) Why can satellite systems be put into service much more rapidly?

10) What can modern telecommunications networks send?

Exercise 7. Say whether the following statements are true or false.

1) Electronic signals carry information to practically any point on the Earth.

2) Mass media send messages to a large number of people.

3) All mass media including postal service are called telecommunications.

4) Telecommunications first appeared with the development of telegraph in
the 1830s and 1840s.

5) The technology used to carry information slightly changed after 1975.

6) Radio communications systems transmit electronic signals in extremely wide frequency bands through the air.

7) Satellite communications permit the exchange of signals by means of microwaves.

8) Satellite stations require the construction of ground-based microwave systems.

9) The still images of facsimile machines or the moving images of video can also be carried by modern telecommunications networks.

10) Modern telecommunications networks transmit only coded data.

Exercise 8. Complete the following sentences choosing the most suitable variant.

1. One type consists of the mass media such as

1. television, radio, newspapers, and magazines.

2. telephone, telegraph, data transmission.

3. television, telephone, telegraph and postal service.

2. The telephone system assumed its modern form with the development of ... during the middle decades of the 20^th century.

1. telegraph traffic

2. dial phoning

3. facsimile machines

3. In most cases telecommunications systems transmit information by

1. open wire, telexes, or faxes.

2. coaxial cable, optical fibers, or global networks.

3. wire, radio, or space satellite.

4. Radio communications systems include

1. radio navigation, radio location and communication

2. radio navigation and both amateur and commercial broadcasting

3. radio detection, TV broadcasting and video television transmissions

5. In optical fibres electrical signals converted to light signals by a laser-driven transmitter carry

1. both encoded data and still images of facsimile machines

2. both voice frequencies and printed messages

3. both speech and data

Exercise 9. Develop the following ideas. Use the words and word-combinations provided in brackets.

1. Communication is the nervous system of our society (any point of the globe; to carry information; to tie together; two types; to transmit; communications media)

2. The origin of telecommunication (great distances; telecommunication; instantly; telegraph; the invention of the telephone; to change; A.G. Bell)

3. The development of telecommunication (wire transmission; radically; speech; enormous masses; technology; computer data; to transmit; coaxial cable; to change; optical fibres; to supplement; global networks)

4. Radio communications systems (public use; band; electronic signals; frequency; to transmit; narrow; commercial broadcasting).

5. Satellite communication (microwaves; television or telephone signals; not to require; repeater stations; to put into operation; to exchange; wavelengths from 4 inches to 0.4 inch; more quickly; frequency range of 3 to 30 GHz).

6. Modern telecommunications networks (business accounts; participants; to carry images; voice communications; to send; telegraph; traditional; telephones; videoconferences; to see and hear; printed messages; medical data; telexes; encoded data.

Exercise 10. Give a summary of the text.

Text B.

Exercise 1. Read and entitle the text.

Telecommunications embraces all devices and systems that transmit electronic signals across long distances. Telecommunications allows people around the world to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information and one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another. Telecommunications devices convert different types of information, such as sound and video, into electronic signals. The signals can then be transmitted by means of media such as telephone wires or radio waves. When a signal reaches its destination, the device on the receiving end converts the electronic signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information and entertainment.

Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one sender to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation between two people or a facsimile (fax) message (see Facsimile Transmission), usually involve point-to-point transmission. Point-to-multipoint telecommunications, often called broadcasts, provide the basis for commercial radio and television programming.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Put 6 questions to the text.

Exercise 3. Retell the text.

Exercise 4. Speak on the following topic: “ What does telecommunications mean?”

UNIT 10

Topic: Wireless Communication: what is it?

Text A. Wireless Communication

Pre-text exercises

Exercise 1. Read the following words and try to remember them.

oscillator – генератор (высоких частот)

transfer – передача

radio frequency – радио частота

convert – преобразовывать, превращать

transceiver – приемопередатчик, радиопередатчик

band – диапазон

disturb – создать помехи

transmission – трансляция, передача

transmitter – передатчик

drawback – изъян, недостаток

device – устройство, прибор

cellular – сотовый (относящийся к радиотелефонной системе)

message – сообщение

broadcast – радиовещание, вещание

decode – расшифровать

wire – электрический провод

Exercise 2. Study the text and try to understand all details.

Wireless Communication

Wireless communications are various telecommunications systems that use radio waves to carry signals and messages across distances. Wireless communications systems use devices called transmitters to generate radio waves. A microphone or other mechanism converts messages, like sounds or other data, into electronic impulses. The transmitters change, or modulate, the radio waves so they can carry the impulses, and then transmit the modulated radio signals across distances. Radio receivers pick up these signals and decode them back into original messages. Commercial radio and television are also wireless telecommunications system, but radio and television are mainly public broadcast services rather than personal communications systems.

Wireless communications allow people greater flexibility while communicating, because they do not need to remain at a fixed location, such as a home or office. Wireless technologies make communications services more readily available than traditional wire-based services (such as ordinary telephones), which require the installation of wires. This is useful in places where only temporary communications services are needed, such as at outdoor festivals or large sporting events. These technologies are also useful for communicating in remote locations, such as mountains, jungles, or deserts, where telephone service might not exist. Wireless services allow people to communicate while in a car, airplane, or other moving vehicle. Police, fire, and other emergency departments use two-way radio to communicate information between vehicles that are already responding to emergency calls, which saves valuable time. Construction and utility workers frequently use hand-held radios for short-range communication and coordination. Many businesspeople use wireless communications, particularly cellular radio telephones, to stay in contact with colleagues and clients while traveling.

All wireless communications devices use radio waves to transmit and receive signals. These devices operate on different radio frequencies so that signals from one device will not overlap and interfere with nearby transmissions from other devices.

2. Principles of Wireless Communications

Wireless communications begin with a message that is converted into an electronic signal by a device called a transmitter. The transmitter uses an oscillator to generate radio waves. The transmitter modulates the radio wave to carry the electronic signal and then sends the modified radio signal out through space, where it is picked up by a receiver. The receiver decodes, or demodulates, the radio wave and plays the decoded message over a speaker. Wireless communications provide more flexibility than wire-based means of communication.

However, there are some drawbacks. Wireless communications are limited by the range of the transmitter (how far a signal can be sent), and since radio waves travel through the atmosphere, they can be disturbed by electrical interferences (such as lightning) that cause static.

Wireless communications systems involve either one-way transmissions, in which a person merely receives notice of a message, or two-way transmissions, such as a telephone conversation between two people. An example of a device that sends one-way transmission is a pager, which is a radio receiver. When a person dials a pager number, the pager company sends a radio signal to the desired pager. The encoded signal triggers the pager circuitry and notifies the customer carrying the pager of the incoming call with a tone or a vibration, and often the telephone number of the caller. Advanced pagers can display short messages from the caller, or provide news updates or sports scores.

Two-way transmissions require both a transmitter and a receiver for sending and receiving signals. A device that functions as both a transmitter and a receiver is called a transceiver. Cellular radio telephones and two-way radios use transceivers, so that back-and-forth communication between two people can be maintained. Early transceivers were very large, but they have decreased in size due to advances in technology. Fixed-base transceivers, such as those used at police stations, can fit on a desktop, and hand-held transceivers have shrunk in size as well. Several current models of hand-held transceivers weigh less than 0.2 kg (0.5 Ib).

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Post-text exercises

Exercise 1. Give Russian equivalents of the following words and word-combinations.

Wireless communication, message, transmitter, broadcast, wire, remote location, valuable time, hand-held radio, convert, oscillator, drawbacks, disturb, shrunk.

Exercise 2. Give English equivalents of the following words and word-combinations.

Данные, дешифровать, эксплуатационная гибкость, требовать, работники строительной компании, с малым радиусом действия, согласованность, сотовый телефон, частота, устройство.

Exercise 3. Match the words with their definitions:

word

definition

1. broadcast

2. decode

3. frequency

4. message

5. communicate

6. drawback

7. receiver

1. pass on news, information, feelings; exchange information;

2. number of repetitions in a given time;

3. piece of news, or a request, sent to something;

4. part of an apparatus for receiving smth., apparatus for receiving broadcast programmes;

5. send out in all direction, especially in radio;

6. smth which lessens one’s satisfaction or makes progress less easy;

7. get the meaning of smth that written in code;

Exercise 4. Use the right word from those given below:

cellular, overlap, to decode, flexibility, converts, dials, band, circuitry, to communicate, charged.

1. One of the functions of radio receivers is ... signals back into the original messages.

2. .Wireless communications provide people with greater... while communicating.

3. . Many businessmen prefer to use ... radio telephones to stay in contact with colleagues and clients.

4. Signals of wireless communications devices mustn't... and interfere with nearby transmissions from other device.

5. .Transmitter... a message into an electronic signal.

6. A radio signal is sent to the desired pager by the pager company when a person ... a pager number.

7. The pager... is triggered by the encoded signal.

8. At present civil authorities use small hand-held radio transceivers ... with each other directly.

9. Amateur or ham radio operators use the shortwave radio ... .

10. Ionized or electrically ... particles in the layer of the atmosphere make shortwave radio broadcasts possible.

Exercise 5. Choose the best answer.

1. The word message means ...

1. a written request;

2. a piece of news or a request sent to smb.;

3. movement of the hand, head, etc. used with or instead of words;

4. a signal.

2. The best explanation of the word transmitter might be...

1. A part of an apparatus for receiving broadcast signals;

2. a person who receives;

3. a part of a telegraph or radio apparatus for sending out signals, messages, etc.;

4. an instrument for recording oscillations.

3. The word frequency implies...

1. excitement;

2. one swing of an electric charge;

3. a vibrating movement;

4. rate of occurrence; number of repetitions (at a given time).

4. The word range refers to ...

1. a variation between limits;

2. a line of persons or things;

3. a position in a scale;

4. a category or class.

5. The word wire means...

1. a radio set;

2. metal drawn out into the form of a thread;

3. a rope;

4. electric current;

6. The best explanation of the word broadcast might be...

1. to give or pass;

2. to send out in all directions, esp. by radio or TV;

3. to help with the hand;

4. to pass by tradition, inheritance.

7. The verb oscillate means...

1. to swing backwards and forwards as the pendulum of a clock does;

2. to move regularly to and fro;

3. to cause smb. to move in a certain direction by waving;

4. to distribute;

Exercise 6. Are the following statements true or false?

1) The transmitters transmit the modulated radio signals across distances.

2) Commercial radio and television aren't wireless communications systems.

3) A person should remain at a fixed location, such as home or office while using wireless communications.

4) Traditional wire-based services make communications services more readily available than wireless technologies.

5. Wireless communications are useful in remote locations where telephone service might not exist.

6. The number of companies offering wireless communications services has decreased in recent years.

7. The transmitter decodes, or demodulates, the radio wave and plays the decoded message over a speaker.

8. The range of the transmitter doesn't limit wireless communications.

Exercise 7. Answer the following questions.

1. What functions do transmitters perform?

2. What functions do receivers perform?

3. What are the advantages of wireless communications?

4. Has the number of companies offering wireless communications services grown steadily in recent years?

5. What are the main principles of wireless communications?

6. How does a pager work?

7. What devices use transceivers?

Exercise 8. Translate the first and last paragraphs of the text.

Exercise 9. Make an outline of the text.

Text B.

Exercise 1. Read the text and try to entitle it.

Wireless communications systems have grown and changed as technology has improved. Several different systems are used today, all of which operate on different radio frequencies. New technologies are being developed to provide greater service and reliability.

A Air Transceivers

Radio operators still monitor distress channels, but maritime and aviation telecommunications systems now use high-frequency radios and satellites capable of transmitting speech, rather than wireless telegraphy, to send messages. Aircraft pilots use radios to communicate with air traffic controllers at airports and also to communicate with other pilots. Navigation beacons are equipped with transmitters that send automated signals to help ships and aircraft in distress determine their positions. While high-frequency radio can transmit signals over long distances, the quality of these signals can be diminished by bad weather or by electrical interference in the atmosphere, which is often caused by radiation from the sun.

В Hand-Held Radio Transceivers

Police, fire, and other emergency organizations, as well as the military, have used two-way wireless radio communication since the 1930s. Early vehicle-based radios were large, heavy units. After the invention of the transistor in 1948, radios shrank in size to small hand-held radio transceivers, which civil authorities now use to communicate with each other directly. Public two-way radios with several frequency options are widely available as well. Usually limited in range to a few miles, these units are great aids for such mobile professionals as construction workers, film crews, event planners, and security personnel. Simpler two-way radios, called walkie-talkies, have been popular children's toys for years.

С Shortwave

Long-range broadcast services and frequencies, in what is known as the shortwave radio band (with frequencies of 3 to 30 megahertz), are available for amateur or ham radio operators. Shortwave radio broadcasts can travel long distances because of the concentration of ionized, or electrically charged, particles in the layer of the atmosphere known as the ionosphere. This layer reflects radio signals, sending signals that are transmitted upward back to earth. This skipping of waves against the ionosphere can greatly increase the range of the transmitter. The degree of reflectivity of the ionosphere depends on the time of day.

D Cellular Radio Telephones

Cellular radio telephones, or cell phones, combine their portable radio capability with the wired, or wireline, telephone network to provide mobile users with access to the rest of the public telephone system used by non-mobile callers. Modern cellular telephones use a network of several short-range antennas that connect to the telephone system. Because the antennas have a shorter range, frequencies can be reused a short distance away without interference.

E Satellite Communications

Satellite communications services connect users directly to the telephone network from almost anywhere in the world. Special telephones are available to consumers that communicate directly with communications satellites orbiting the earth. The satellites transmit these signals to ground stations that are connected to the telephone system. These satellite services, while more expensive than cellular or other wireless services, give users access to the telephone network in areas of the world where no telephone service exists.

The number of companies offering wireless communications services has grown steadily in recent years. In 1988 about 500 companies offered cellular radio telephone (cell phone) services. By 1995 that number had grown to over 1500 companies serving millions of subscribers. Wireless communication is becoming increasingly popular because of the convenience and mobility it affords, the expanded availability of radio frequencies for transmitting, and improvements in technology.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Exercise 2. Put 5 questions to the text.

Exercise 3. Retell the text.

Exercise 4. Be ready to talk about: “What are the merits and demerits of the wireless communication”.

ADDITIONAL TEXTS

Text 1. Passive Elements in Radioelectronic Apparatus

Passive elements in electrical circuits are the elements that do not generate energy. They include resistors, capacitors, inductance coils, transformers, oscillatory circuits.

Units in which resistance is deliberately created are known as resistors. They are used either to reduce the current to a desired value or to produce a specific voltage drop external to the voltage source. Resistors are available in a wide range of values, from a fraction of an ohm to many megohms.

Inductance coil is a coil of wire with an air or iron core through which an alternating current is passed. The inductance of coil depends on the number of turns, the cross-sectional area and the material inside the coil. The unit of inductance is the henry.

A transformer is a static electromagnetic apparatus operated on the basis of induction. It consists of two coils (primary and secondary) which have mutual inductance between them. These two coils are coupled by means of mutual inductance. With the help of transformer we can transfer the energy from one circuit to another and also change it from one voltage level to another. There exist step-up and step-down transformers.

The device known as a condenser (capacitor) consists of two conducting plates, separated by an insulating material called a dielectric. A condenser is capable of storing electrical energy.

The property of two electrical conductors, separated by a dielectric, to receive and retain electrical charges is known as capacity. It depends upon the area of the plates, the distance between them and upon the nature of dielectric. The unit of capacitance is the farad.

An oscillatory circuit includes a capacitor connected to a self-inductance coil. The electric properties of such a circuit are determined by the capacitance the capacitor, the inductance of the coil and the resistance of the entire circuit.

*(В.Г. Златніков Практичний курс з вивчення іноземної мови студентів 4 курсу за спеціальністю “Радіоелектронні пристрої, системи та комплекси”. Київ – 2006. стр 136)

Text 2. Vacuum Tubes

Though ousted in many spheres of application, electron valves present some interest as they are still in use.

An electron tube has a glass or metal envelope enclosing metal electrodes in a vacuum. The electrodes enable the electrons to flow through the evacuated space inside the tube. The electrode which emits electrons is the cathode. Generally, the cathode is heated by a wire filament, which results in thermionic emission of electrons.

The electrode that collects the emitted electrons is the anode, or plate. The plate has a positive potential applied with respect to the cathode, so that the emitted electrons are attracted to provide plate current. Between the cathode and the anode the tube can also have the third electrode - a wire serving as a control grid to increase or decrease electron flow to the plate.

There are two advantages in using a vacuum tube to provide current. First, the emitted electrons can flow in only one direction from the cathode to the plate inside the tube. Thus, the tube serves as a rectifier, changing alternating current into direct current.

Second, the amount of plate current can be controlled by the grid, so that in practice, a small potential on the grid can control a much larger potential on the plate. Therefore, the tube can be used as an amplifier for electrical variations.

The diode is used as a half-wave rectifier. Two diodes can be used in a full-wave rectifier circuit.

In the triode the control grid determines how many electrons from the space charge can be attracted by the positive plate to provide plate current. The more negative the control grid voltage is, the less the plate current.

*(В.Г. Златніков Практичний курс з вивчення іноземної мови студентів 4 курсу за спеціальністю “Радіоелектронні пристрої, системи та комплекси”. Київ – 2006. стр.139)

Text 3. Transistors

A transistor is an entirely new type of electron device consisting of two p-n junctions. Transistors are far smaller than tubes, have no filament and hence need no heating power. They are mechanically rugged, have practically unlimited life and can do some jobs better than electron tubes.

A p-n-p junction is known to be made up of a sandwich of two p-n germanium junction diodes, placed back to back. The centre of the n-type portion of the sandwich is extremely thin in comparison with the p-regions. If a potential difference is applied to the junction transistor so that the p-regions are negative with respect to the central n-region, the mobile electrons in the n-region, therefore, move away from both the junctions in the direction of the positive connecting terminal. The holes in each of the p-region also move away from the junctions and are attracted toward the negative terminals. Under this condition the current flow stops. The n-p-n transistor is similar to the p-n-p transistor except that polarities are reversed. Transistors are widely used in various amplifiers, receivers, oscillators and many other electronic devices.

In recent years the transistor - an entirely new type of electron device has replaced the electron tubes in many applications. In contrast to electron tubes the transistor relies for its operation on the movement of charge carriers through a solid state, a semiconductor.

When transistors are operated as an amplifier three basic circuit connections are possible. These are:

1. common- base

2. common - emitter

3. common - collector

The common - emitter circuit is the most efficient of the three basic connections. The common - collector connection provides a high input resistance, a low output resistance and about the same gain as the common - emitter circuit.

The common - base connection provides a very low input resistance and a high output resistance.

The bipolar transistor

The bipolar junction transistor consists of two junctions formed by a sandwich of doped semiconductor material. These bipolar transistors may be of p-n-p or n-p-n type. In the n-p-n transistor a thin layer or lightly doped p-type material (base) is placed between two thicker layers of n-type material (emitters collector). In the p-n-p transistor the base is made up of n-type material. The base layer may be as thin as one micron. When the circuit is closed the base-emitter junction becomes forward - biased allowing a current to flow in the collector -emitter circuit. This is transistor action. Thus, the transistor is a current -controlled device. The current gain is the ratio of collector current to the base current. In a typical small silicon transistor the current gain is of the order of 100.

*(В.Г. Златніков Практичний курс з вивчення іноземної мови студентів 4 курсу за спеціальністю “Радіоелектронні пристрої, системи та комплекси”. Київ – 2006. стр. 146)

Text 4. The basic elements of a telecommunication system

The basic elements of a telecommunication system are:

1. a transmitter that takes information and converts it to a signal for transmission;

2. a receiver that receives and converts the signal back into usable information.

For example, consider a radio broadcast. In this case, the broadcast tower is

the transmitter, the radio is the receiver and the transmission medium is free space. Often telecommunication systems are two-way and devices act as both a transmitter and receiver or transceiver. For example, a mobile phone is a transceiver. Telecommunication over a phone line is called point-to-point communication because it is between one transmitter and one receiver, telecommunication through radio broadcasts is called broadcast communication because it is between one powerful transmitter and numerous receivers.

Signals can either be analogue or digital. In an analogue signal, the signal is varied continuously with respect to the information. In a digital signal, the information is encoded as a set of discrete values (e.g. 1 's and O's).

A collection of transmitters, receivers or transceivers that communicate with each other is known as a network. Digital networks may consist of one or more routers that route data to the correct user. An analogue network may consist of one or more switches that establish a connection between two or more users. For both types of network, a repeater may be necessary to amplify or recreate the signal when it is being transmitted over long distances. This is to combat noise which can corrupt the information carried by a signal.

A channel is a division in a transmission medium so that it can be used to send multiple independent streams of data. For example, a radio station may broadcast at 96 MHz while another radio station may broadcast at 94.5 MHz. In this case the medium has been divided by frequency and each channel received a separate frequency to broadcast on. Alternatively one could allocate each channel a segment of time over which to broadcast.

The shaping of a signal to convey information is known as modulation. Modulation is a key concept in telecommunications and is frequently used to impose the information of one signal on another. Modulation is used to represent a digital message as an analogue waveform. This is known as keying and several keying techniques exist —these include phase-shift keying, amplitude-shift keying and minimum-shift keying. Bluetooth, for example, uses phase-shift keying for exchanges between devices.

However, more relevant to earlier discussion, modulation is also used to boost the frequency of analogue signals. This is because a raw signal is often not suitable for transmission over free space due to its low frequencies. Hence its information must be superimposed on a higher frequency signal (known as a carrier wave) before transmission. There are several different modulation schemes available to achieve this — some of the most basic being amplitude modulation and frequency modulation. An example of this process is a DJ's voice being superimposed on a 96 MHz carrier wave using frequency modulation (the voice would then be received on a radio as the channel "96 FM").

*(В.Г. Златніков Практичний курс з вивчення іноземної мови студентів 4 курсу за спеціальністю “Радіоелектронні пристрої, системи та комплекси”. Київ – 2006. стр. 157)

Text 5. RADIO. AM and FM

Originally, radio technology was called 'wireless telegraphy', which was shortened to 'wireless'. The prefix radio- in the sense of wireless transmission was first recorded in the word radioconductor, coined by the French physicist Edouard Branly in 1897 and based on the verb to radiate. 'Radio' as a noun is said to have been coined by advertising expert Waldo Warren (White 1944). The word appears in a 1907 article by Lee de Forest, was adopted by the United States Navy in 1912 and became common by the time of the first commercial broadcasts in the Unite States in the 1920s. (The noun 'broadcasting' itself came from an agricultural term meaning 'scattering seeds'.) The American term was then adopted by other languages in Europe and Asia, although Britain retained the term 'wireless' until the mid-20th century.

In Chinese, the term 'wireless' is the basis for the term 'radio wave' although the term for the device that listens to radio waves is literally 'device for receiving sounds'.

AM broadcast radio sends music and voice in the Medium Frequency (MF— 0.300 MHz to 3 MHz) radio spectrum. AM radio uses amplitude modulation, in which louder sounds at the microphone causes wider fluctuations in the transmitter power while the transmitter frequency remains unchanged. Transmissions are affected by static because lightning and other sources of radio add their radio waves to the ones from the transmitter.

FM broadcast radio sends music and voice, with higher fidelity than AM radio. In frequency modulation, louder sounds at the microphone cause the transmitter frequency to fluctuate farther, the transmitter power stays constant. FM is transmitted in the Very High Frequency (VHF—30 MHz to 300 MHz) radio spectrum. FM requires more radio frequency space than AM and there are more frequencies available at higher frequencies, so there can be more stations, each sending more information. Another effect is that shorter VHF radio waves act more like light, travelling in straight lines, hence the reception range is generally limited to about 50-100 miles. During unusual upper atmospheric conditions, FM signals are occasionally reflected back towards the Earth by the ionosphere, resulting in Long distance FM reception. FM receivers are subject to the capture effect, which causes the radio to only receive the strongest signal when multiple signals appear on the same frequency. FM receivers are relatively immune to lightning and spark interference.

FM Subcarrier services are secondary signals transmitted ‘’piggyback’’ along with the main program. Special receivers are required to utilize these services.

Analog channels may contain alternative programming, such as reading services for the blind, background music or stereo sound signals. In some extremely crowded metropolitan areas, the subchannel program might be an alternate foreign language radio program for various ethnic groups. Subcarriers can also transmit digital data, such as station identification, the current song's name, web addresses, or stock quotes. In some countries, FM radios automatically retune themselves to the same channel in a different district by using sub-bands.

Aviation voice radios use VHF AM. AM is used so that multiple stations on the same channel can be received. (Use of FM would result in stronger stations blocking out reception of weaker stations due to FM's capture effect). Aircraft fly high enough that their transmitters can be received hundreds of miles (kilometres) away, even though they are using VHF.

Marine voice radios can use AM in the shortwave High Frequency (HF—3 MHz to 30 MHz) radio spectrum for very long ranges or narrowband FM in the VHF spectrum for much shorter ranges.

Government, police, fire and commercial voice services use narrowband FM on special frequencies. Fidelity is sacrificed to use a smaller range of radio frequencies, usually five kHz of deviation, rather than the 75 kHz used by FM broadcasts and 25 kHz used by TV sound.

Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements. Most use single sideband voice (SSB), which uses less bandwidth than AM. On an AM radio SSB sounds like ducks quacking. Viewed as a graph of frequency versus power, an AM signal shows power where the frequencies of the voice add and subtract with the main radio frequency. SSB cuts the bandwidth in half by suppressing the carrier and (usually) lower sideband. This also makes the transmitter about three times more powerful, because it doesn't need to transmit the unused carrier and sideband.

TETRA, Terrestrial Trunked Radio is a digital cell phone system for military, police and ambulances.

Commercial services such as XM, WorldSpace and Sirius offer encrypted digital Satellite radio.

*(В.Г. Златніков Практичний курс з вивчення іноземної мови студентів 4 курсу за спеціальністю “Радіоелектронні пристрої, системи та комплекси”. Київ – 2006. стр. 168-169)

Text 6. British achievements in science and technology in the 20^th century

Britain has a long tradition of research and innovation in science, technology and engineering in universities, research institutes and industry. Its record of achievement in the 20^th century is in many ways unsurpassed. For example, fundamental contributions to modern genetics were made through the discovery of the three-dimensional molecular structure of DNA (deoxyribonucleic acid) and of cholesterol, vitamin D, penicillin and insulin.

Notable contributions in other areas over the past 25 years have been made in improving the understanding of the nature and origin of the universe; in superconductivity (abnormally high electrical conductivity at low temperatures); in radio astrophysics; and in computer assisted tomography (a form of radiography) for medical diagnosis.

Much pioneering work was done during the 1980s. For example, in 1985 British scientists discovered the hole in the ozone layer over the Antarctic. In the same year was invented DNA fingerprinting, a forensic technique which can identify an individual from a small tissue sample. More recently there have been several British breakthroughs in genetics research, including the identification of the gene in the Y-chromosome responsible for determining sex, and the identification of the other genes linked to diseases, including inherited heart disease. A vaccine has been developed to protect against cancer. The world’s first pig to have a genetically modified heart has been bred by scientists at Cambridge University, an important milestone in breeding animals as organ donors for people.

*(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Text 7. Electric shock and safety electric system

The strength of current depends on both the voltage and the resistance in a circuit. A current of 50 ma is dangerous for a man; it may result in an electric shock. One gets an electric shock in case one touches live conductors when the power is on. And a current of 100 ma and higher is lethal. Thus, before working on a circuit, deenergize it and work on it with the power off.

Earthing system serves to protect attending personnel from electric shocks when voltage appears on parts that are normally dead. The risk of an electric shock decreases with decreasing voltage. In wet and hot atmosphere the risk of electric shock increases. Safe voltage for circuits used in dry atmosphere is under 36 V. When the power is on contacts with live conductors are dangerous for life. When a live conductor is touched with both hands the resistance of the conductor is from 10.000 to 50.000 ohms. When a live conductor is touched with one hand the resistance is much higher. The higher is the body resistance, the smaller is the current that flows through the body. Take it into consideration and work with one hand if the power is on! Or work on the circuit with the power off!

Thus measures are taken to protect attending personnel from contacts with live parts of installations under voltage.

The danger of electric shock disappears provided the metal parts of installations under voltage are connected with ground by means of safety earthing. Connecting to ground is made by means of measuring devices. The faulty parts should be detected, eliminated, and replaced by new ones.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Text 8. Electricity and magnetism

It has been known for centuries that certain black heavy stones have the property of attracting iron, this property is called magnetism. A body that exhibits magnetism is called a magnet. The two parts of a magnet that show the strongest magnetism are called the north-pole and south-pole.

Magnets not only affect ordinary iron, but they affect one another. When a pole of one magnet is brought toward a pole of the second magnet, they will repel if both are north-poles or both south-poles, but they will attract if one is the north-pole and the other is the south-pole.

The region in which magnetic forces act is called a magnetic field.

When placed in a strong magnetic field, iron becomes magnetized.

Electricity and magnetism are closely connected. Almost all metals are good conductors of electricity, with cooper being one of the best conductors of all. Glass, paper, rubber are the most common non-conductors or insulators.

Many practical applications have resulted from the utilization of the magnetic effect of an electricity current.

These effects are used in motors, in most electric meters (amperometers, voltmeters, galvanometers), in electromagnets and practically in all electromechanical apparatus.

(Source: Internet http/elib.bsuir.unibel.by/rubrics/1_0_1/local_doc.html)

Abbreviation

a. c. alternating current

a. f. audio frequency

cm(s) centimeter (s)

c. p. s. (c/s) cycles per second

d. c. direct current

e. g. for example

e. m. f., emf electromotive force

etc. and so on

e. v. electron-volt

hr(s) hour(s)

i. e. that is

i. f. intermediate frequency

kc kilocycle

km (s) kilometer(s)

mc megacycle

mm(s) millimeter(s)

n-p-n negative-positive-negative

p. h. per hour

p. m. per minute

p-n-p positive-negative-positive

p. s. per second

r. f. radio frequency

t. r. f. tuned radio frequency

v. s. versus

viz. namely

Белянская Н. Г. Шкарупа О. Г.

Reader for Second-Year Students of Radioengineering Department

(Part 1)

Пособие для студентов второго курса радиотехнического факультета

(Часть 1)