Q.Draw the block diagram of an FM receiver and explain its working.

An FM receiver is a superheterodyne receiver with a 10.7 MHz IF and two extra stages - an amplitude limiter and an FM detector (discriminator) - plus a de-emphasis network, because information in FM is carried by frequency rather than amplitude. …

[!TLDR]

An FM receiver is a superhet with 10.7 MHz IF, adding a limiter (to strip amplitude noise), an FM discriminator (frequency-to-audio) and a de-emphasis network before the audio stages.

An FM receiver also uses the superheterodyne principle but includes stages specific to FM. Its blocks and their functions are:

1. RF amplifier: selects and amplifies the wanted FM signal (88-108 MHz band), improves the signal-to-noise ratio and rejects the image frequency.
2. Mixer: beats the RF signal with the local oscillator to produce the fixed intermediate frequency.
3. Local oscillator: generates $f_{LO}=f_s+10.7$ MHz, ganged with the RF tuning, so the difference is the fixed IF of 10.7 MHz.
4. IF amplifier: a fixed-tuned 10.7 MHz amplifier providing most of the gain and selectivity.
5. Limiter (amplitude limiter): clips the signal to a constant amplitude, removing any amplitude variations and noise picked up in the channel; this is possible because in FM the information is in the frequency, not the amplitude, and it is a major reason for FM's superior noise performance and fidelity.
6. FM detector (discriminator / ratio detector): converts the frequency variations of the FM signal into the corresponding audio (amplitude) variations, thereby recovering the modulating signal. …