FM modulation

FM stands for “Frequency Modulation“. In FM modulation, the frequency of a radio wave is used to carry the information, such as speech or music. The signal is modulated, or changed, in such a way that the frequency of the carrier wave (the wave that is being used to transmit the signal) is made to vary in accordance with the frequency of the modulating signal (the signal that is carrying the information).

In an FM signal, the carrier wave is a sine wave of constant amplitude and frequency. The modulating signal, which contains the information, is also a sine wave, but its frequency is varied in order to transmit the information. As a result, the frequency of the carrier wave will also vary in the same way.

The advantage of FM over AM is that it is less affected by noise and interference, as the variations in the frequency of the signal are much harder to disrupt than the variations in the amplitude of an AM signal. FM also has a much wider frequency deviation and therefore can support higher quality audio.

FM is widely used in many applications, such as in television and radio broadcasting, two-way radios, and wireless microphones. FM is also commonly used in citizens band (CB) radios, but it is not as common as AM.