"The continuous good fortune which has followed me, providing second chances at inventions when the first chance was missed and tossed away, has been all that a man could hope for and more than he has any right to expect."
Edwin Howard Armstrong (1890–1954)
Armstrong invented three of the electronic circuits fundamental to modern radio, television, and radar. The first was a new "regenerative" circuit, based on the audion tube, which eventually yielded the first radio amplifier. The second was a complex eight-tube receiver, known as the superheterodyne circuit, that amplified weak signals to a degree previously impossible. This circuit, which Armstrong invented while serving as an officer in the U.S. Army Signal Corps during World War I, remains a basic component of nearly all radio and television receivers today. Most notably, he designed an entirely new system—wide-band frequency modulation (FM)—that offered the highest-fidelity sound yet heard in radio. In World War II he again served in the army, aiding troops in the use of FM radio. Plagued from his early inventing years onwards by legal battles with corporations over the rights to his inventions, Armstrong committed suicide in 1954.