Edwin Howard Armstrong (1890-1954), American electrical engineer and inventor of basic electronic circuits essential to modern radio, radar, and television. Often noted as one of the radio's leading inventors, Armstrong invented the regenerative circuit (1912), which revolutionized wireless radio communication by amplifying weak radio signals without distortion far more effectively than other radio receivers of that time; the superheterodyne circuit (1918), which further improved the ability to receive radio signals; and the complete Frequency Modualtion (FM) system (1933) that would eventually displace Amplitude Modulation (AM) technology. In 1940, Armstrong was issued a permit to build the first FM station, which he erected at his own expense on the Hudson River Palisades at Alpine, N.J.
- Hong, Sungook, 2004. A History of the Regerative Circuit: From Invention to Patent Litigation (PDF), School of Biological Sciences, Seoul National University.
- Public Broadcasting Service (PBS.org). Who Made America?.