In the context of communication, specifically in FM receivers, AFC stands for Automatic Frequency Control.
Automatic Frequency Control (AFC) is a circuit that automatically maintains the correct tuning of a receiver. It compensates for frequency drift in the receiver's oscillator or in the received signal itself. In an FM receiver, AFC is particularly important because the demodulator's output voltage is highly dependent on the input frequency. Without AFC, slight frequency variations could significantly degrade the audio quality.
Essentially, the AFC system constantly monitors the frequency of the received signal and adjusts the local oscillator in the receiver to ensure that it remains precisely tuned to the incoming signal's frequency. This ensures optimal demodulation and prevents distortion or signal loss.
