Edwin Armstrong

Edwin Howard Armstrong was an American electrical engineer and longtime professor at Columbia University whose four major radio-circuit inventions, the regenerative circuit, the superheterodyne receiver, the super-regenerative circuit and wide-band frequency modulation, underpinned nearly all subsequent radio technology. He developed the regenerative circuit as a Columbia undergraduate around 1912, enabling far greater amplification than earlier vacuum-tube designs, and in 1933 he received five patents for FM radio, which the Federal Communications Commission used as the basis for the first commercial FM broadcast band in 1941. He held 42 patents in total and received the Institute of Radio Engineers Medal of Honor in 1917 and the Franklin Institute's Franklin Medal in 1941. His later career was consumed by bitter patent litigation, first against Lee de Forest over the regenerative circuit and then against RCA over FM, disputes that drained his finances and, in February 1954, contributed to his suicide.