The sinusoidal modulating wave m (t) = Am cos (2mt) is applied to a phase modulator with

The sinusoidal modulating wave m (t) = Am cos (2πƒmt) is applied to a phase modulator with phase sensitivity kp. The unmodulated carrier wave has frequency ƒc and amplitude Ac.

(a) Determine the spectrum of the resulting phase-modulated signal, assuming that the maximum phase deviation βp = k p, Am does not exceed 0.3 radians.

(b) Construct a phasor diagram for this modulated signal, and compare it with that of the corresponding narrowband FM signal.