Radio's premier inventor, Armstrong created the electronic circuits that form the foundation of all modern radio, radar, and television technologies: the regenerative circuit, the superheterodyne circuit, and a complete FM system. While a junior at Columbia University, he designed a regenerative circuit that became the first radio amplifier and the key to the continuous-wave transmitter. As a U.S. Army Signal Corps officer in Paris during World War I, Armstrong adapted a little-used technique called heterodyning to design a receiver that amplified weak signals to a previously unheard-of degree. The superheterodyne circuit remains the basic component in virtually all radio and television receivers. In 1933, Armstrong's wide-band FM system provided clear reception through the most violent storms and the highest fidelity yet heard in radio.
