题目

英语翻译
Amplitude Modulation
Amplitude modulation (AM) is a modulation technique in which the amplitude of a high frequency sine wave (usually at a radio frequency) is varied in direct proportion to that of a modulating signal.The modulating signal carries the required information and often consists of audio data,as in the case of AM radio broadcasts or two-way radio communications.The high frequency sine wave (the carrier) is modulated by adding the modulating signal to it in a mixer.A simplified AM radio transmitter system is shown below.A simple form of amplitude modulation was originally used to modulate audio voice signals onto a low-voltage direct current (dc) carrier on a telephone circuit.A microphone in the telephone handset acts as a transducer,and uses the sound waves produced by the human voice to vary the current passing through the circuit.At the other end of the telephone line,a second transducer (in the form of a small loudspeaker mounted in the remote handset) us

提问时间：2020-08-07

答案

全是翻译机器翻的..