Greenleaf Whittier Pickard
Greenleaf Whittier Pickard (February 14, 1877 – January 8, 1956) was an American electrical engineer and inventor. He is best known for helping develop the crystal detector, the first practical diode detector used in early radios. The crystal detector was a key part of radio receivers from about 1906 to 1920. Pickard also studied antennas, radio wave propagation, and ways to reduce electrical noise.
Born in Portland, Maine, Pickard studied at Harvard University and the Massachusetts Institute of Technology. He filed a patent for a silicon crystal detector on August 30, 1906, which was granted November 20, 1906. He followed with a patent for a “Magnetic Aerial” (a loop aerial) on June 10, 1907, granted January 21, 1908. On June 21, 1911, he patented a crystal detector using a springy low-inertia wire with a loop or helix to make contact with the crystal; this design, often called the cat whisker detector, was granted July 21, 1914.
Pickard was named after his great-uncle, the Quaker John Greenleaf Whittier, and he was the grandson of author Mathew Franklin Whittier. He served as president of the Institute of Radio Engineers in 1913 and won the IRE Medal of Honor in 1926. He died in Newton, Massachusetts, at the age of 78.
This page was last edited on 2 February 2026, at 16:15 (CET).