Frequency modulation的意思|示意

Frequency modulation (FM) is a form of modulation used in radio transmission to transmit or receive sound, such as music or other audio signals. It is based on the principle of changing the frequency of the signal, rather than its amplitude.

In frequency modulation, the frequency of the carrier wave is varied based on the audio signal. This gives FM signals a much greater range than amplitude modulation (AM) signals, which are limited to a smaller range. FM signals are also less affected by interference or noise than AM signals, making them ideal for use in radio broadcasting.

FM signals are usually transmitted at a frequency of 88 to 108 Megahertz, although higher frequencies can be used in some cases. The frequency of the signal is then varied using an audio signal, allowing sound to be transmitted. The audio signal is transmitted as part of the modulated carrier wave, and is detected at the receiver end.

Frequency modulation can be used for both analog and digital transmission. In analog FM, the frequency of the carrier is changed in a continuous manner, with the variations in the amplitude or frequency representing the audio signal. In digital FM, the audio signal is encoded digitally and sent as a series of pulses.

FM transmission is widely used in radio broadcasting, as well as in television transmission. It is also widely used in other forms of communication, such as cellular phones and satellite systems.