Inventor of the Week Archive
for a different Invention or Inventor
Howard Armstrong, the "father of FM radio," was born on December 18, 1890 in
New York City. He grew up in Yonkers, New York, and knew by the age of fourteen
that he wanted to become an inventor. He began tinkering with homemade wireless
gadgets as a teenager, and as a high school student, he build an antenna mast
on his family's front lawn to study wireless technology. He quickly identified
a problem: there was no device in existence that could amplify weak signals
at the receiving end of a communications transmission, nor was there a way to
provide stronger power at the sending end. After he finished high school, he
entered Columbia University's school of engineering
where he pursued his wireless studies further.
During his third year at Columbia, Armstrong came up with his first major
invention: the first radio amplifier. He had learned how Lee DeForest's
radio tube worked, then he redesigned it by taking the electromagnetic waves
that came from a radio transmission and repeatedly feeding the signal back through
the tube. Each time, the signal's power would increase as much as 20,000 times
a second. This phenomenon, which Armstrong called "regeneration," was an extremely
important discovery in the early days of radio. With this development, radio
engineers no longer needed 20-ton generators to get their stations on the air.
Armstrong's single-circuit design provided the key to the continuous-wave transmitter
that is at the core of radio operations today. He graduated with his B.S. in
engineering in 1913. He patented his creation and licensed it to the Marconi
corporation, in 1914.
Soon after graduation, Armstrong was sent to Paris to serve in World War I.
There he came up with his second major invention, the superheterodyne receiver,
after he had been put on a project to improve ability to intercept shortwave
enemy communications. The superheterodyne receiver is still part of virtually
every tuner in today's radios, televisions and radars. In 1920, Westinghouse bought Armstrong's patent for
the superheterodyne receiver, and started up the nation's first radio station,
KDKA, in Pittsburgh. Radio became very popular at about this time, and more
and more stations came to the airwaves. The Radio Corporation of America, or
RCA soon bought up all of Westinghouse's radio patents,
as well as the patents of other competitors.
By then, Armstrong was back at Columbia University working as a professor.
In 1923 he married Marion MacInnes, secretary to the president of RCA, David
Sarnoff. Later that decade he became embroiled in a corporate war for control
of radio patents. This continued through the early part of the 1930s, and Armstrong
was unsuccessful in most of his court battles. Meanwhile, however, he pursued
a solution to the problem of static in radio. By the late 1920's he had decided
the only solution was to design an entirely new system. In 1933 he presented
the wide-band frequency modulation (FM) system, which gave clear reception even
in storms and offered the highest fidelity sound yet heard in radio. The system
also allowed for a single carrier wave to transmit two radio programs at once.
This development was called "multiplexing."
In 1940 Armstrong got a permit for the first FM station, which he established
in Alpine, New Jersey. In 1941 the Franklin Institute awarded Armstrong
the Franklin Medal, one of the science community's highest honors. However,
Armstrong, having unsuccessfully battled giant corporations for years who were
profiting from his patents, committed suicide in 1954. His widow continued to
fight Armstrong's legal battles, and she won millions of dollars in damages
over the next several years. By the late 1960's, FM was established as the superior
radio system, and is even used in earth-to-space communication.