Which inventor developed frequency modulation, the radio technology known as FM, patented in 1933?

Edwin Howard Armstrong developed frequency modulation, the radio technology known as FM, patented in 1933.

Armstrong’s FM system encoded sound by varying the frequency of a radio carrier rather than mainly varying its amplitude. This greatly reduced the effect of static and electrical interference, producing clearer audio than conventional AM broadcasts under many conditions.

He demonstrated wideband FM in the 1930s and built an FM station at Alpine, New Jersey. The technology initially faced resistance from established radio interests and regulators, but it eventually became the basis of high-fidelity broadcast radio.

Armstrong also made major contributions to radio before FM. He invented the regenerative circuit and the superheterodyne receiver, both important developments in early radio engineering. FM radio should not be confused with the invention of radio itself, which involved several earlier pioneers.