What is the full form of FM
FM: Frequency Modulation
FM stands for Frequency Modulation. It is also called Frequency Modulated Electromagnetic Wave. It is generally used for FM broadcasting and various other radio communication applications. In Telecommunication, Frequency Modulation is a technique of transmitting information using a carrier wave. The frequency of the carrier wave is varied according to the amplitude and polarity of the input signal. FM and AM both are used for radio broadcasting but FM is different from AM. AM stands for Amplitude Modulated Electromagnetic Wave. AM is prone to interference because the amplitude of AM signals can be altered easily. On the other hand FM is much less prone to interference because the amplitude of FM signals cannot be altered easily.
History
The FM broadcasting technology was invented by Edwin Howard Armstrong. It was invented in the early 1930’s.
Benefits of FM broadcasting
- FM is less prone to noise because the FM signal’s information is varied through frequency variation, not in amplitude variation.
- The frequency range of FM radio is higher comparatively. It ranges from 88 to 108 MHz or 1200 to 2400 bits per second.
- FM produces better sound quality due to higher bandwidth.
- FM is known for its good audio quality so FM radio is also known as High Fidelity sets.
- In FM broadcasting, it is possible to use non-linear RF amplifiers to amplify FM signals.
- FM is resilient to signal-variation that makes it suitable for mobile applications where signal levels vary constantly.
- In FM broadcasting, modulation can be applied to a low power stage of the transmitter.
Common Applications
- FM Radio: FM radios use a modulation index (m>1) which is called wideband FM.
- Television Sound: In terrestrial TV broadcasts, the video signal is transmitted through AM and sound signal is transmitted through FM. It helps reduce interference between video and sound signals.
- Satellite TV: Some of the TV transmissions use FM to broadcast an analogue video signal. It helps obtain an acceptable signal at the receiving end.