Astrophysics (index)about

frequency modulation

(changing the frequency of a signal's carrier)

Frequency modulation (FM) is changing the frequency of a signal's carrier. In communications using a continuous sinusoidal signal, information can be encoded in a pattern of changes to the frequency. In FM radio, the pattern is the pattern of air pressure to produce sounds being communicated.

Frequency modulation is used in radar, such as in chirps and in continuous-wave frequency-modulated (CWFM) radar, which has some of the advantages of using chirped pulses as well as the advantage of having no gaps in the received information when the radar and target are not relatively static.