**Ernst Adolph Guillemin** (May 8, 1898 – April 1, 1970) was an American electrical engineer and computer scientist at the Massachusetts Institute of Technology who spent his career extending the art and science of linear network analysis and synthesis.

Guillemin was born in 1898, in Milwaukee, and received his B.S. (1922) and S.M. (1924) degrees in electrical engineering from the University of Wisconsin–Madison and MIT, respectively. He then attended the University of Munich, under Arnold Sommerfeld, on a Saltonstall Traveling Fellowship. He was granted his doctorate in 1926, whereupon he returned to MIT as an instructor, becoming Assistant Professor in 1928, Associate Professor in 1936, and Professor in Electrical Communications in 1944. In 1960, he was appointed to the MIT Edwin Sibley Webster Chair of Electrical Engineering, a title he held until his retirement in 1963.

On the invitation of Edward L. Bowles in 1928, Guillemin was invited to assist in the development of a communications option for undergraduate students. In this effort, he revised and expanded a subject that included communication transmission lines, telephone repeaters, balancing networks, and filter theory. Thus began his lifelong career of developing and refining linear, lumped, finite, passive, and bilateral networks in the sphere of teaching.

Guillemin was appointed consultant to the Microwave Committee of the National Defense Research Committee in 1940. As such, he spent about half of his time consulting with groups in the MIT Radiation Laboratory. He took over administrative responsibility of the Communications Option in the MIT Department of Electrical Engineering, in 1941.

During his career, Guillemin influenced many undergraduate and graduate students who went on to contribute greatly in industry and academia; included in the list are his graduate students Robert Fano and Thomas Stockham. His professional contributions were recognized internationally with numerous honors and awards.

Memberships
Fellow of the American Academy of Arts and Sciences (1955)
Fellow of the American Institute of Electrical Engineers
Fellow of the Institute of Radio Engineers
Foreign Fellow of the British Royal Society of Arts
Honors
1948 – President's Certificate of Merit for his outstanding contributions during World War II
1961 – IRE Medal of Honor from the Institute of Radio Engineers
1962 – American Institute of Electrical Engineers Education Medal
1960 - Appointed the first Edwin Sibley Webster Professor
Ernst A. Guillemin has written several books:

1931. *Communication Networks* (Wiley)
1935. *Communication Networks: Vol. II The Classical Theory of Long Lines, Filters and Related Networks* (Wiley)
1941. *Notes for Principles of Electrical Communications 6.30* (MIT)
1944. *The Mathematics of Circuit Analysis: Vol. 1 Reference Volumes for Collateral Study - Principles of Electrical Engineering Series* (Department of Electrical Engineering, MIT)
1955. *Introductory Circuit Theory* (Wiley)
1960. *Linear System Theory* (Guillemin)
1962. *Synthesis of Passive Networks Theory and Methods Appropriate to the Realization and Approximation Problems* (Wiley)
1963. *Theory of Linear Physical Systems: Theory of Physical Systems from the Viewpoint of Classical Dynamics, Including Fourier Methods* (Wiley)
1963. *Theory of Linear Physical Systems* (Wiley)
1967. *Synthesis of Passive Networks: Theory and Methods Appropriate to the Realization and Approximation Problems* (Wiley)
1969. *The Mathematics of Circuit Analysis: Extensions to the Mathematical Training of Electrical Engineers - Principles of Electrical Engineering Series* (MIT)