Scanning the Past

Scanning the Past: A History of Electrical Engineering from the Past

Submitted by Dick Reiman, Historian

George C. Southworth

Fifty years ago this month, the PROCEEDINGS OF THE IRE (Institute of Radio Engineers) included a paper on microwaves by George Southworth of the Bell Telephone Laboratories. He had pioneered in the use of hollow-pipe waveguides for the transmission of microwaves, which, at the time of his 1943 paper, were enjoying extensive use in radar systems. Because of wartime secrecy, he did not provide specific details on current military applications of microwaves, but he noted that among current trends "perhaps none has been more spectacular than that toward the higher frequencies." He observed that the high-frequency frontier had "surged forward almost as a flood." Southworth pointed out that microwaves made it possible to employ antennas of great directivity and to transmit information over long distances using microwave relay towers. Alternatively, he noted that long waveguide systems might be used although he thought it was too early to tell which system would win out. He concluded that a radical new technology involving microwaves was emerging which would provide new challenges and opportunities for electrical engineers.

Southworth was born in Little Cooley, Pennsylvania, in 1890 and became interested in radio while still in high school. He graduated with a degree in physics from Grove City College in 1914 and then studied for a year at Columbia University. In June 1917 he joined the Radio Section of the U.S. National Bureau of Standards and assisted in the preparation of the influential Bulletin 74 entitled Radio Instruments and Measurements, published in1918. In September 1918 he went to Yale University to teach in a Signal Corps training school for Army officers and he remained on at Yale to complete a doctorate in 1923. His doctoral thesis was on the measurement of the dielectric constant of water at frequencies above 15 MHz.

Since he already had a family to support, Southworth decided to give up his teaching position at Yale in favor of a higher-paying job with the American Telephone and Telegraph Company. Initially he was assigned to assist the editor of the Bell System Technical Journal, but was transferred to the Department of Development and Research to do research on shortwave radio propagation. In 1931 he began a study of wave propagation in dielectric rods, although the project did not yet have official authorization. By early 1932, he observed wave propagation in a water-filled copper pipe. Theoretical analysis related to Southworth's experiments was carried out by John R. Carson, Sergei A. Schelkunoff, and Sallie P. Mead during 1932.

Using high-frequency vacuum tubes imported from France, Southworth transmitted waves through air-filled copper pipes up to 20 feet long by May 1933. He later recalled that the first message sent through a waveguide was "Send money." After he demonstrated the waveguide to his superiors in July 1933, he received authorization to construct a 5-in.-diameter guide with a length of 875 ft for further tests. In 1934 Southworth and his waveguide project were moved to the Bell Telephone Laboratories, and he relocated to Holmdel, New Jersey. He directed a small team of two other engineers and a technician over the next four years in the development of waveguide technology, including instrumentation. He presented an IRE paper on his work on waveguides in April 1936 and it was published in the PROCEEDINGS in July 1937.

Southworth received the Morris N. Liebmann award from the IRE in 1938 and the IEEE Medal of Honor in 1963. In 1950 he published a book entitled Principles and Applications of Waveguide Transmission. He retired from the Bell Laboratories in 1955 although he continued to do consulting work. His autobiography, Forty years of Radio Research, was published in 1962. He received about thirty U.S. patents during his career. He died in 1972 at the age of 81.

James E. Brittain

School of History, Technology, and Society, Georgia Institute of Technology