Frequencymodulaatio

Frequencymodulaatio, often abbreviated as FM, is a method of encoding information in an analog signal by varying the carrier wave's frequency. In FM, the amplitude of the carrier wave remains constant, while its frequency is altered in proportion to the instantaneous amplitude of the modulating signal. This contrasts with amplitude modulation (AM), where the carrier wave's amplitude is varied.

The process of frequency modulation involves a carrier wave and a modulating signal. The carrier wave is a high-frequency signal that is transmitted. The modulating signal, which contains the information to be transmitted (such as audio), changes the frequency of the carrier wave. The extent of this frequency change, known as the frequency deviation, is directly proportional to the amplitude of the modulating signal. A larger amplitude in the modulating signal results in a greater frequency deviation.

FM is widely used in radio broadcasting, particularly for high-fidelity stereo sound, due to its inherent resistance to noise. Fluctuations in the received signal's amplitude, which are often caused by static or interference, are largely ignored by an FM receiver, as it primarily focuses on frequency variations. This characteristic makes FM broadcasts generally clearer and less prone to static than AM broadcasts. FM is also utilized in other applications, including telecommunications, radar, and certain types of audio synthesis.