FM means frequency modulation, and it refers to the encoding of a waveform by changing (modulating) the frequency of another. This is the technology used in broadcast FM radio transmission:



This is how FM radio communication works: by modulating the frequency of a radio-frequency (RF) signal according to the amplitude of the voltage signal produced by a microphone.



Explain how a phase-locked loop circuit could be used to demodulate the output of an FM radio station, so as to extract the broadcasters audio signal from the RF waveform.