Frequency modulation

Frequency modulation (FM) was devised as a method of reducing static interference in radio transmissions by altering the frequency of the carrier signal instead of its amplitude. It allowed for clearer reception, but was limited in range.
 Edwin Howard Armstrong United States 1939 Frequency modulation

Frequency modulation (FM) was devised as a method of reducing static interference in radio transmissions by altering the frequency of the carrier signal instead of its amplitude. It allowed for clearer reception, but was limited in range.