In discussing amplitude modulation systems, modulation and demodulation were carried out...

In discussing amplitude modulation systems, modulation and demodulation were carried out through the use of a multiplier. Since multipliers are often difficult to implement, many practical systems use a nonlinear element. In this problem, we illustrate the basic concept.

In Figure P8.34, we show one such nonlinear system for amplitude modulation. The system consists of squaring the sum of the modulating signal and the carrier and then bandpass filtering to obtain the amplitude-modulated signal.