{{short description|American electronics engineer (1929-2016)}} {{Infobox scientist | honorific_prefix = | name = Nathan O. Sokal | honorific_suffix = | native_name = | native_name_lang = | image = <!--(filename only, i.e. without "File:" prefix)--> | image_size = | image_upright = | landscape = <!-- yes, if wide image, otherwise leave blank --> | alt = | caption = | birth_name = <!-- if different from "name" --> | birth_date = {{birth date |1929|02|01}} | birth_place = Brooklyn, New York City, U.S. | death_date = {{death date and age |2016|05|08 |1929|02|01}} | death_place = Newton, Massachusetts | death_cause = <!-- should only be included when the cause of death has significance for the subject's notability --> | education = Stuyvesant High School | fields = Electrical engineering | workplaces = {{plainlist| *Philco *Massachusetts Institute of Technology *MIT Lincoln Laboratory *Design Automation, Inc. }} | alma_mater = Massachusetts Institute of Technology | thesis_title = Area display of obstacle location for use with a guidance device for the blind | thesis_url = https://dspace.mit.edu/handle/1721.1/103686 | thesis_year = 1950 | known_for = Class E RF power amplifiers | awards = | children = 3, including Alan }}
'''Nathan O. Sokal''' (February 1, 1929 – May 8, 2016) was an American electrical engineer and inventor. He is best known for his contribution to the design of RF power amplifiers and the development of class E power amplifiers.
==Biography== Sokal was born in 1929 in Brooklyn. He was born to a family of Polish-Jewish descent who emigrated to the United States in 1924. His parents were medical doctors. Attending Stuyvesant High School in the 1940s,<ref name="upm-obituary"/> he received B.S. and S.M degrees in electrical engineering in 1950 from Massachusetts Institute of Technology;<ref name="microwave"/> his masters studies were advised by O. H. Straus.<ref name="masters"/> During his studies in MIT, he was a co-op student and worked at Philco during alternate semesters. His work at Philco ranged from the design of control and electronics units for radar systems to the electrical testing of loudspeakers and thyratrons.<ref name="mtt-bio"/> In 1952, He married Zelda Kaufman Sokal, a fellow New Yorker and a student at Radcliffe College. They had three children: physicist and professor Alan Sokal, Karen Sokal-Gutierrez and Diane Sokal.<ref name="microwave"/>
Following his graduation, Sokol held engineering and supervisory positions in various companies, including Mack Trucks and Sylvania Electric Products. He became a staff member at MIT, and served as a United States Air Force lieutenant from 1954 to 1956. During his tenure at Holmes and Narver, Inc., he worked on instrumentation and data recording of blast effects for nuclear tests at Enewetak Atoll. Subsequently, he became an engineer at MIT Lincoln Laboratory, where he worked on the design, manufacturing, installation and operation of analog and digital equipment. In 1965, he founded the electronics consulting firm Design Automation, Inc., which provided product design, design review and redesign, and technology development, particularly on power electronics for switching mode power conversion and amplification below 2.5 GHz frequencies.<ref name="memoriam"/>
Sokal is best known for his work on high-efficiency RF power amplifiers, which was motivated by his interest in amateur radio.<ref name="class-e"/> In the 1970s, he, along with his son Alan, introduced the class E switching-mode power amplifier.<ref>{{cite journal |last1=Sokal |first1=N. O |last2=Sokal |first2=A. D. |title=Class E-A new class of high-efficiency tuned single-ended switching power amplifiers |journal=IEEE Journal of Solid-State Circuits |date=1975 |volume=10 |issue=3 |pages=168–176 |doi=10.1109/JSSC.1975.1050582}}</ref> Sokal also invented a high-efficiency linear RF power amplifier using envelope elimination and restoration. His inventions were subject to multiple patents. In 1989, he was elected as an IEEE fellow for his contributions to the technology of high-efficiency power conversion and RF power amplification.<ref name="memoriam"/> In 2007, he, along with his son Alan, received the Microwave Pioneer Award "in recognition of a major, lasting contribution of the development of the class-E high-efficiency switching-mode RF power amplifier."<ref name="mtt-pioneer"/> In 2007, he received a honorary doctorate from Technical University of Madrid for his work on RF power amplifiers.<ref name="memoriam"/>
Sokal died on 8 May 2016 in Newton, Massachusetts, and was survived by his wife, three children and six grandchildren.<ref name="memoriam"/>
==Selected publications== ;Books * {{cite book |last1=Grebennikov |first1=Andrei |last2=Franco |first2=Marc J. |last3=Sokal |first3=Nathan O. |title=Switchmode RF and Microwave Power Amplifiers |date=2012 |publisher=Academic Press |isbn=0080550649}}
;Journal articles * {{cite journal |last1=Sokal |first1=N. O |last2=Sokal |first2=A. D. |title=Class E-A new class of high-efficiency tuned single-ended switching power amplifiers |journal=IEEE Journal of Solid-State Circuits |date=1975 |volume=10 |issue=3 |pages=168–176 |doi=10.1109/JSSC.1975.1050582 |author-link2=Alan Sokal}} * {{cite journal |last1=Raab |first1=F. H. |last2=Sokal |first2=N. O. |title=Transistor power losses in the class E tuned power amplifier |journal=IEEE Journal of Solid-State Circuits |date=1978 |volume=13 |issue=6 |pages=912–914 |doi=10.1109/JSSC.1978.1052069}} * {{cite journal |last1=Sokal |first1=N. O. |title=Class E high-efficiency switching-mode tuned power amplifier with only one inductor and one capacitor in load network-approximate analysis |journal=IEEE Journal of Solid-State Circuits |date=1981 |volume=16 |issue=4 |pages=380–384 |doi=10.1109/JSSC.1981.1051605}} * {{cite journal |last1=Redl |first1=Richard |last2=Molnar |first2=Bela |last3=Sokal |first3=Nathan O. |title=Class E resonant regulated DC/DC power converters: analysis of operations, and experimental results at 1.5 MHz |journal=IEEE Transactions on Power Electronics |date=1986 |volume=PE-1 |issue=2 |pages=111–120 |doi=10.1109/TPEL.1986.4766289}} * {{cite journal |last1=Redl |first1=R. |last2=Sokal |first2=N.O. |last3=Balogh |first3=L. |title=A novel soft-switching full-bridge DC/DC converter: analysis, design considerations, and experimental results at 1.5 kW, 100 kHz |journal=IEEE Transactions on Power Electronics |date=1991 |volume=6 |issue=3 |pages=408–418 |doi=10.1109/63.85909}} * {{cite journal |last1=Raab |first1=F. H. |last2=Asbeck |first2=P. |last3=Cripps |first3=S. |last4=Kenington |first4=P. B. |last5=Popovic |first5=Z. B. |last6=Pothecary |first6=N. |last7=Sevic |first7=J. F. |last8=Sokal |first8=N. O. |title=Power amplifiers and transmitters for RF and microwave |journal=IEEE Transactions on Microwave Theory and Techniques |date=2002 |volume=50 |issue=3 |pages=814–826 |doi=10.1109/22.989965}}
;Patents * {{cite patent |country=US |number=3900823 |status=patent |title=Amplifying and processing apparatus for modulated carrier signals |invent1=Nathan O. Sokal |invent2=Alan D. Sokal|gdate=August 15, 1975}} * {{cite patent |country=US |number=3919656 |status=patent |title=High-efficiency tuned switching power amplifier |invent1=Nathan O. Sokal |invent2=Alan D. Sokal|gdate=November 11, 1975}} * {{cite patent |country=US |number=4607323 |status=patent |title=Class E high-frequency high-efficiency DC/DC power converter |invent1=Nathan O. Sokal | invent2=Richard Redl |invent3=Bela Molnar|gdate=August 19, 1986}} * {{cite patent |country=US |number=4719559 |status=patent |title=Current-mode control of capacitively coupled power converters |invent2=Richard Redl |invent1=Nathan O. Sokal |gdate=January 12, 1988}} * {{cite patent |country=US |number=4928200 |status=patent |title=Overcurrent protection for switching mode power converter |invent1=Richard Redl |invent2=Nathan O. Sokal |gdate=May 22, 1990}} * {{cite patent |country=US |number=5485361 |status=patent |title=Flyback charging with current mode controlled flyback converter |inventor=Nathan O. Sokal |gdate=January 16, 1996}}
==References== {{Reflist|refs=
<ref name="class-e">{{cite journal |last1=Sokal |first1=Nathan O. |title=The Origin and Development of the High Efficiency Class-E RF Power Amplifier: A 2011 Address Accepting the Honorary Doctorate |journal=IEEE Microwave Magazine |date=2018 |volume=19 |issue=5 |pages=22–25 |doi=10.1109/MMM.2018.2823241}}</ref>
<ref name="mtt-pioneer">{{cite web |title=2007 Microwave Pioneer Award |url=https://mtt.org/app/uploads/2019/01/2007_A_Sokal.pdf |website=mtt.org |access-date=December 28, 2025}}</ref>
<ref name="masters">{{cite thesis |last=Sokal |first=Nathan O. |date=1950 |title=Area display of obstacle location for use with a guidance device for the blind |url=https://dspace.mit.edu/handle/1721.1/103686 |work= |degree=S.M. |location= |publisher=Massachusetts Institute of Technology |access-date=}}</ref>
<ref name="memoriam">{{cite journal |last1=Hausner |first1=Jerry |title=Nathan (Nat) Sokol [In Memoriam] |journal=IEEE Microwave Magazine |date=2016 |volume=17 |issue=10 |pages=80–81 |doi=10.1109/MMM.2016.2589421}}</ref>
<ref name="microwave">{{cite journal |last1=Raab |first1=Frederick H. |title=Recollections of Nathan Sokal: The Man, His Work, and the Class-E Amplifier |journal=IEEE Microwave Magazine |date=2018 |volume=19 |issue=5 |doi=10.1109/MMM.2018.2823240}}</ref>
<ref name="mtt-bio">{{cite web |title=Biography: Nathan O. Sokal |url=https://mtt.org/profile/nathan-o-sokal/ |website=mtt.org |access-date=December 28, 2025}}</ref>
<ref name="upm-obituary">{{cite web |title=Obituary: Nathan (Nat) Sokal |url=https://www.etsist.upm.es/uploaded/eventos/Actualidad-Prensa/Nathan%20Sokal%20obituary%20with%20photo-1.pdf |website=upm.es |publisher=Technical University of Madrid |access-date=December 29, 2025}}</ref> }}
==External links== * [https://mtt.org/profile/nathan-o-sokal/ Biography of Nathan O. Sokal] at IEEE Microwave Theory and Technology Society
{{DEFAULTSORT:Sokal, Nathan O}} Category:1929 births Category:2016 deaths Category:Scientists from Brooklyn Category:Engineers from Boston Category:20th-century American engineers Category:21st-century American engineers Category:20th-century American inventors Category:21st-century American inventors Category:American microwave engineers Category:MIT Lincoln Laboratory people Category:MIT School of Engineering alumni Category:Massachusetts Institute of Technology staff Category:20th-century American businesspeople Category:21st-century American businesspeople Category:20th-century American Jews Category:21st-century American Jews Category:Amateur radio people Category:American people of Polish-Jewish descent Category:United States Air Force personnel Category:Fellows of the IEEE Category:Jewish American scientists Category:Stuyvesant High School alumni Category:Engineers from Brooklyn Category:Inventors from Brooklyn