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 radio broadcasting method that uses frequency modulation (FM) transmissions. 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 began development of wide-band FM. This offered 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 broadcasts.
FM radio stations are usually assigned to transmit on very high frequency (VHF) radio frequencies.