Edwin Howard Armstrong—Inventive Genius

Abstract

No inventor contributed more profoundly to the science of electronic communication than did Edwin Howard Armstrong. Armstrong invented the three basic electronic circuits that are used in all modern radio, radar, and television equipment. One of the maior problems in the early days of radio was how to amplify weak signals. In 1912, Armstrong invented the regenerative circuit—the first reliable means of amplifying radio waves. He improved amplification by inventing the superheterodyne circuit in 1918 and the superregenerative circuit in 1920. Having solved the problem of amplification, Armstrong turned his attention to reducing interference and static in radio receivers. His research in this area led to his invention of frequency modulation (FM) in 1933. Up to that time, all receivers used amplitude modulation (AM). The development of FM made static-free broadcasting and reception possible. Edwin Armstrong was born in New York City on Dec. 18, 1890. Stimulated by the work of Marconi, Armstrong became interested in radio communication early in life. By the age of 17 years, he had built his own radio station. In 1913, Armstrong received a degree in electrical engineering from Columbia University. From 1914 to 1935, he did research at Columbia with the famous physicist and inventor Michael Pupin, and in 1936, he became a professor at Columbia. During World War I, Armstrong served in the United States Army Signal Corps and was sent to Paris to detect enemy shortwave communications. This assignment led to the previously mentioned invention of the superheterodyne circuit in 1918—the basic circuit in 98% of all radio and television receivers. Although Armstrong invented FM in 1933, it was not readily accepted by the established industry or the Federal Communications Commission. This reluctance was a source of much concern to him. Throughout his life, he fought legal battles concerning patents and patent infringements, some of which he won and others that he lost. Having spent most of his wealth in the fight to establish FM, the ill and aging Armstrong committed suicide on Feb. 1, 1954. Armstrong received many honors during his lifetime, including the highest awards of the two electrical engineering societies, the American Institute of Electrical Engineering (Edison Medal in 1942) and the Institute of Radio Engineers (Medal of Honor in 1918). He also received the Franklin Medal in 1941 for his work during the war and the United States Medal for Merit in 1945. His portrait is depicted on one of the stamps honoring American inventors that was issued by the United States in 1983.