born Aug. 7, 1886, Morristown, N.J., U.S.
died May 24, 1964, Maplewood, N.J.
U.S. electrical engineer and physicist.
In the early 1920s he invented the neutrodyne circuit, which made commercial radio possible by neutralizing the noise that plagued all radio receivers of the time; by 1927 some 10 million radio receivers were using the device. Hazeltine later advised the U.S. government on regulation of radio broadcasting, and during World War II he served on the National Defense Research Committee.