FMmoduláció

FM moduláció, or frequency modulation, is a method of encoding information onto a carrier wave by varying its frequency. The frequency of the carrier wave is altered in proportion to the instantaneous amplitude of the message signal. This means that as the message signal's amplitude increases, the carrier wave's frequency shifts higher, and as the message signal's amplitude decreases, the carrier wave's frequency shifts lower. The amplitude of the carrier wave remains constant.

This type of modulation is widely used in radio broadcasting, particularly for FM radio stations. Its primary advantage over amplitude modulation (AM) is its greater immunity to noise and interference. Because noise often manifests as amplitude variations, FM receivers can effectively ignore these fluctuations, resulting in a clearer signal. FM is also used in other applications such as two-way radios, satellite communications, and some forms of audio synthesis.

The process of FM involves a modulator that takes the message signal and the carrier wave as inputs. The modulator adjusts the carrier frequency based on the message signal's amplitude. At the receiver, a demodulator, often a frequency discriminator or a phase-locked loop, detects the changes in frequency and reconstructs the original message signal. The bandwidth required for FM is generally wider than for AM, which is a trade-off for its improved noise performance. The frequency deviation, which is the maximum shift in the carrier frequency from its center frequency, is a key parameter in FM system design.