FM broadcasting
| FM broadcasting | |
|---|---|
| Frequency modulation | |
AM and FM modulated signals for radio. AM (amplitude modulation) and FM (frequency modulation) are types of modulation. The sound of the program material, usually coming from a radio studio, is used to modulate (vary) a carrier wave of a specific frequency, then broadcast.
In AM broadcasting, the amplitude of the carrier wave is modulated to encode the original sound. In FM broadcasting, the frequency of the carrier wave is modulated to encode the sound. A radio receiver extracts the original program sound from the modulated radio signal and reproduces the sound in a loudspeaker. | |
| Abbreviation | FM |
| Status | Active |
| Year started | 1933 |
| Authors | Edwin Howard Armstrong |
| License | Public |
| Website | www |
FM broadcasting is a method of radio broadcasting that uses frequency modulation (FM) to modulate the carrier wave. In November 1919, Hans Idzerda began broadcasts, using narrow-band FM, over station PCGG, located at The Hague in the Netherlands. However, most early broadcasting stations instead employed Amplitude Modulation (AM) transmissions.
In 1933, American engineer Edwin Armstrong invented wide-band FM, which is used worldwide to transmit high-fidelity sound over broadcast radio. FM broadcasting offers higher fidelity—more accurate reproduction of the original program sound—than other analog broadcasting techniques, such as AM broadcasting. It is also less susceptible to common forms of interference, having less static and popping sounds than are often heard on AM, but with a more limited broadcast distance. Therefore, FM is used for most broadcasts of music and general audio (in the audio spectrum). FM radio stations use the very high frequency range of radio frequencies.