The frequencies of two side bands in an AM wave are 640 kHz and 660 kHz respectively. Find the frequencies of carrier and modulating signal. What is the bandwidth required for amplitude modulation?

Explanation

Let the frequencies of carrier and modulating signal be denoted by `f_(c) and f_(m)` respectively.
According to the problem ,
`f_(c) + f_(m) = 600`
`f_(c) -f_(m)`= 640
`therefore" " f_(c) = (600 + 640)/(2) = (1300)/(2) = 650 kHz`
and `f_(m) = (660 -640)/(2) = (20)/(2) = 10kHz`
Hence, the bandwidth required for amplitude modulation = 660 - 640 = 20 kHz