TEXT 2. Amplitude Modulation

Переведите текст с русского языка на английский

Amplitude, broadcasts, carrier, narrowband, bandwidth

1. The … form is used for voice communications in commercial and amateur radio. 2. Frequency modulation requires a wider … than amplitude modulation by an equivalent modulating signal. 3. Frequency modulation (FM) is a technique used to mix (encode) an information-carrying signal onto a much higher sine wave … frequency. 4. Wideband FM (W-FM) requires a wider signal bandwidth than … modulation by an equivalent modulating signal. 5. Since the amplitude is kept constant, FM modulation is a low-noise process and provides a high quality modulation technique which is used for music and speech in hi-fidelity....

9. Вставьте пропущенные предлоги:

1. When a signal is modulated … the radio frequency carrier, the new radio frequency signal moves up and down … frequency. 2. Wide-band signals are capable … supporting high-quality transmissions. 3. One of the advantages of FM is its resilience … noise and interference. 4. Another advantage of FM is associated … the transmitters. 5. It is possible to apply FM … a lower power stage of transmitters and use non-linear RF amplifiers.

10. Переведите предложения с английского языка на русский:

1. It is possible to use efficient RF amplifiers with frequency modulated signals. 2. The spectrum of an FM wave consists of a carrier wave with a series of pairs of sidebands. 3. Ionospheric refraction doesn't appreciably affect FM or TV signals because of their higher frequency. 4. The unmodulated frequency of a FM signal is called its center frequency. 5. The amount of "swing" in the transmitter's frequency in any direction above or below the center frequency is called its deviation. 6. The total frequency space occupied by a FM signal is twice its deviation. 7. FM is often encountered by the general public in the form of FM radio broadcasting, which supports high fidelity sound and stereophonic reproduction.

ЧМ- вид модуляции, при которой частота сигнала несущей изменяется в соответствии с аналоговым информационным сигналом. Наиболее распространенный вид модуляции радиосвязи в КВ (SW) и УКВ диапазонах. По сравнению с АМ менее подвержен зашумлению и помехам. Есть два подвида - узкая и широкая частотная модуляция. Все известные приемники способны принимать оба подвида.

12. Выучите следующие слова и выражения:

accurately ['ækjərətlɪ] - точно, безошибочно, аккуратно

interfere [ˌɪntə'fɪə] - 1. интерферировать,пересекаться, скрещиваться

2) (interfere with) служить препятствием, мешать, быть помехой (чему-л.)

superimpose [ˌs(j)uːp(ə)rɪm'pəuz] (on) - накладывать (одно на другое)

sum [sʌm] - сумма, количество, величина, итог, совокупность.

reference ['ref(ə)r(ə)n(t)s] - справка; справочная информация

predominant [prɪ'dɔmɪnənt] - господствующий, преобладающий

vestigial sideband signal [ ves'tɪʤɪəl ] - сигнал с частично подавленной боковой полосой

13. Прочитайте и устно переведите текст:

Amplitude modulation (AM) is one of the earliest and easiest radio modulation techniques. In this case the radio frequency signal has a representation of the data (a sound wave) superimposed in it.

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