Walter Guyton Cady

Who was Walter Guyton Cady?

Dr. Walter Guyton Cady was a noted American physicist and electrical engineer. He was a pioneer in piezoelectricity, and in 1921 developed the first crystal oscillator.

Cady was born in Providence, Rhode Island, graduated from Brown University in 1895, and studied 1897-1900 at the University of Berlin, receiving his Ph.D. in Physics in 1900. He was a Magnetic Observer from 1900-1902 with the Coast and Geodetic Survey, and from 1902-1946 he was a professor of physics at Wesleyan University, where his principal interests included electrical discharges in gases, piezoelectricity, ultrasound, piezoelectric resonators and oscillators, and crystal devices.

Before World War I, Cady investigated arc discharges and radio detectors, but during the war became interested in crystals as he worked with General Electric Company's Research Laboratory, Columbia University, and the Naval Experimental Station in New London, Connecticut, on using high-frequency sound generated by piezoelectricity to detect submarines. His early experiments employed Rochelle salt crystals as transducers. After noticing that a quartz crystal connected to a variable-frequency electronic oscillator would vibrate strongly at a very specific frequency, but that at other frequencies it would not vibrate at all, he had the insight to apply crystal oscillators to radio frequency applications.