William C. Pittman Jr.
Defense technology engineer
Life Senior Member, 94; died 21 October
Pittman was supervisor of the telemetry group that worked on Redstone, a family of rockets that comprised American ballistic missiles, sounding rockets, and expendable launch vehicles.
He served in the U.S. Marine Corps during World War II, then was recruited by the Army to work as a civilian on rocket development at the Ordnance Missile Laboratories, in Huntsville, Ala. He was promoted to group supervisor for the Army’s telemetry system, developed for the Redstone program, and his work focused on studying the atmosphere’s effects on rocket-tracking systems.
The Redstone missile went on to power the Jupiter C rocket, which launched the first U.S. orbiting satellite. A modified Redstone missile topped with NASA’s Mercury capsule, Freedom 7, launched the first U.S. astronaut into space, Alan Shepard.
Pittman, who retired as a senior engineer in 1999, continued until 2012 to volunteer as a researcher for the military. He was inducted in 2014 into the Army Materiel Command Hall of Fame for his work with the Redstone program. The AMC Hall of Fame honors people who have made significant and enduring contributions to the Army.
Pittman was a member of the IEEE Microwave Theory and Techniques Society.
He earned bachelor’s and master’s degrees in electrical engineering from Mississippi State University, in Starkville.
George L. Allerton
Life Senior Member, 95; died 10 March
Allerton was an electrical engineer at Western Electric Co., a primary supplier of AT&T’s telecommunications equipment.
He joined the company in 1945 and retired 35 years later. He was awarded his 10th U.S. patent at the age of 93. His patents were for electromagnetic and microwave components.
Allerton was a member of the IEEE Components, Packaging, and Manufacturing Society.
He enjoyed spending time with his family, playing board games, and exploring the outdoors.
Pioneer of MOSFET technology
Life Fellow, 84; died 6 May
Critchlow was a researcher at IBM for 35 years. He began his career in 1956 as an assistant professor at Carnegie Tech (now Carnegie Mellon University), in Pittsburgh. Two years later he joined IBM’s Thomas J. Watson Research Center, in Yorktown, N.Y. There he researched tunnel diode circuits and high-speed modems. Throughout the 1960s and 1970s his work focused on metal oxide semiconductor field-effect transistor (MOFSET) technology for logic and memory.
In 1976 he joined IBM’s microelectronics division. He retired from the company in 1993, and for the next 13 years he was an adjunct professor at the University of Vermont, in Burlington.
He was elevated to IEEE Fellow in 1985 “for contributions to the research and development of LSI [large-scale integration] and VLSI [very large-scale integration] MOSFET technologies.”
He was a member of the IEEE Computer and IEEE Electron Devices societies. He was also an IBM fellow, a member of the National Academy of Engineering, and a founding member of the Vermont Academy of Science and Engineering.
Critchlow, an avid cyclist and woodworker, was also active in the First Congregational Church of Burlington.
He received a bachelor’s degree in electrical engineering in 1953 from Grove City College, in Pennsylvania. He went on to earn a master’s degree in 1954 and a Ph.D. in 1956, both in EE, from Carnegie Tech.
Nathan O. Sokal
Power amplifier inventor
Life Fellow, 87; died 8 May
Sokal was as an electronics engineer for more than 60 years.
During the 1950s he was a member of the research staff at MIT Lincoln Laboratory, in Lexington, Mass., where he designed and tested electronics.
In 1965 he founded Design Automation, in Lexington, which specialized in electronics engineering design and consulting. He served as president of the company for decades.
Sokal invented the Class E high-efficiency power amplifier in the early 1970s with his son, Alan. Such amplifiers use a transistor as an on/off switch and shape the voltage and current waveforms to prevent simultaneous high voltage and high current in the transistor, thus minimizing power dissipation. Its invention contributed to the development of many modern conveniences including cellphones and microwave ovens.
In 1989 he was elevated to IEEE Fellow “for contributions to technology of high-efficiency power conversion and RF-power amplification.” He and his son both received the 2007 IEEE Microwave Pioneer Award for their amplifier invention.
He enjoyed nature and outdoor activities including hiking, skiing, cycling, and canoeing. He also enjoyed ballroom dancing with his wife Zelda and traveling the world with her.
He received bachelor’s and master’s degrees in electrical engineering from MIT, plus an honorary doctorate in 2011 from the Polytechnic University of Madrid.
Jack F. Butler
Life Senior Member, 83; died 10 May
Butler specialized in lasers and semiconductor materials.
He served in the U.S. Marine Corps in the 1950s, and later worked as a physicist at MIT Lincoln Laboratory, General Dynamics, and Arthur D. Little.
He founded two technology companies. In 1975 he launched Laser Analytics in Lexington, Mass., and served as its president until 1980. In 1985 he founded Digirad Corp. in San Diego, and was its president until 1998.
He earned bachelor’s, master’s, and doctoral degrees in electrical engineering from the University of California, Berkeley.