William H. Doherty

Who was William H. Doherty?

William H. Doherty was an American electrical engineer noted for his invention of the Doherty amplifier.

Doherty was born in Cambridge, Massachusetts, received his B.S. degree in electrical communication engineering in 1927 and M.S. degree in engineering in 1928, both from Harvard University. After a few months in the American Telephone and Telegraph Company Long Lines Department in Boston, he joined the National Bureau of Standards to study radio phenomena. In 1929 he began work at Bell Telephone Laboratories where he developed high power radio transmitters for transoceanic radio telephones and broadcasting.

In 1936 he invented a means to greatly improve the efficiency of RF power amplifiers, quickly termed the "Doherty amplifier". It was first used in a 500-kilowatt transmitter made by Western Electric Company for WHAS, Louisville, Kentucky, but the Federal Communications Commission restricted broadcast stations to 50 kilowatts maximum power. By 1940 Western Electric had incorporated Doherty amplifiers in 35 commercial radio stations worldwide.

Doherty received the 1937 IEEE Morris N. Liebmann Memorial Award for his improvement in the efficiency of radio-frequency power amplifiers.