FM (Frequency Modulation)

A means of convenying information on a carrier wave by varying its instantaneous frequency. In an audio application, like FM radio, the wanted audio signal's amplitude is used to create corresponding deviations in the carrier wave's frequency.  A demodulator can detect these frequency variations and converts them back to amplitude variations to recover the base-band audio signal. This form of modulation contrasts with amplitude modulation (AM) where the carrier wave frequency remains constant and its amplitude is varied to convey the wanted signal.