Generation of Indirect FM signal

Change in instantaneous phase of the carrier with change in amplitude of the modulating signal generates

Options:

Direct FM
Indirect FM
SSB-SC
DSB-SC

Correct Answer: Indirect FM

Explanation:

Indirect FM is obtained by modulation of the phase of the carrier i.e., the instantaneous phase of the carrier varies with the amplitude of the modulating signal. Crystal controlled oscillators are used to generate Indirect FM and then the result is passed through a frequency multiplier to convert the signal into wideband FM signal.