IN MEMORIAM — Prof. Alfred Fettweis
Vojin Oklobdzija
His longtime colleague and friend Dr. Joos Vandewalle, Life Fellow of IEEE and former Vice Dean of the University of Leuven where Dr. Fettweis obtained his doctorate provided us with in depth summary of his professional life:
“During his career he made many visionary contributions to engineering and science that were ahead of his time. In fact, great practitioners of science or engineering have always anticipated in tempore non-suspecto laws and design concepts that were much later confirmed by observation or implementation. During his doctorate in 1963, Fettweis first demonstrated mathematically that it is possible to construct filters by using only capacitors and periodically controlled switches thereby avoiding the use of costly inductances. However, given that, at that time, such switches were difficult to realize, this work was considered for a long time a mathematical curiosity. Fourteen years later, due to progress in the semiconductor technology, cheap MOS transistor switches could be fabricated, and the theory of Fettweis was, to a certain extent, reinvented in the United States and now provides, as switched capacitor circuits, the ideal method to realize inexpensive filters for analog signals on integrated circuits. Today, every electronic switchboard contains tens of thousands of such filters with switched capacitors. At the end of the sixties, when computers were still a curiosity, Fettweis foresaw that the accuracy and reliability of today’s communication systems could only be achieved through digitalization. Sound and picture should be represented by numbers, which should be processed by billions of calculations per second. Until then, however, it was not clear how to come up with mathematical algorithms that had, with a limited number of operations, as good or better properties than the classical analog filters that were devised by the top network theorists in the first half of the previous century. Drawing on a deep understanding of the theory and on strict mathematical principles, Prof. Fettweis invented the so-called wave digital filters, whose superior qualities are now recognized worldwide making lasting contribution to modern network theory and signal processing. As our world was gradually becoming a world of images and graphics, he discovered the more dimensional wave digital filters with the same excellent mathematical properties. These can now be integrated in chips and perform successfully more dimensional filtering as needed in high quality TV systems, and portable devices. Like most great men in art and science, he combined an immense interdisciplinary wisdom, natural intelligence for the creation of basic concepts and the enthusiasm for teaching these to the next generation. During his years in industry he experienced from inside that visionary basic engineering science does exist and can in the long run lead to great economic returns. His love for science, art and people, and deep respect for the art of teaching and worldwide involvement in the professional society are reflected in his many international recognitions and social contributions. He leaves us with a lasting legacy.”
An orally recorded interview with Alfred Fettweis, that is also transcribed, can be downloaded from the Engineering and Technology History Wiki. It contains many important landmarks of his life. A notable detail is that Eupen, the city of his birth and childhood, switched countries 3 times between Belgium and Germany in the first half of the previous century, due to war and peace treaties. Dr. Fettweis was a citizen of Belgium and Germany. http://ethw.org/Oral-History:Alfred_Fettweis
A short bio of Dr. Fettweis:
Professor Fettweis received his engineering degree (ingenieur civil électricien) and his doctoral degree (doctor en sciences appliquées) from Université Catholique de Louvain, Leuven, Belgium, in 1951 and 1962, respectively. He attended graduate courses at Columbia University and Polytechnic Institute of Brooklyn, both NY, in 1954 to 1956.
From 1951 to 1963 he was a development engineer with the International Telephone & Telegraph Corporation (ITT) in Antwerp, Belgium, and on assignment in the US (1954-56). From 1963 to ’67 he was professor (Theoretical Electricity) at TU Eindhoven, Netherlands. Since 1967 he was professor (Communications Engineering) at Ruhr-University Bochum, Germany, also consulting industry from 1963-92. During 1994-96 he was Distinguished Professor at the University of Notre Dame, USA. He published two books, and papers in English/French/German/Dutch in various areas of circuits and systems, communications, digital signal processing, numerical integration, and physics, as well as science related general topics. He held 30 patents. His IEEE activities included the positions of Vice President Region 8 (1987), member of the Administrative Committee (AdCom) (1973-75) and the Board of Governors (1995-97), all of the IEEE CAS Society, TPC Chairman of ISCAS Munich in 1976, Co-Chairman of the CAS Technical Committee on Digital Signal Processing (1982-86), as well as Co-Guest Editor (1978) and Overseas Associate Editor (1977-79) of the IEEE Trans. on Circuits and Systems, as well as member of various IEEE Committees, in particular of the CAS Society.
Alfred Fettweis was a recipient of the Prix Acta Technica Belgica 1962-63, the 1980 Darlington Prize Paper Award of the IEEE CAS Society, the Prix George Montefiore 1980 (Belgium), the IEEE Centennial Medal 1984, the VDE Ehrenring 1984, the 1988 IEEE CAS Technical Achievement Award, the Karl-Küpfmüller-Preis 1988 of the ITG/VDE, the Basic Research Award of the Eduard-Rhein-Stiftung, 1993, the 1992 Peter-Johns Prize for the best paper of the Int. Journal of Numerical Modeling, the 1990 Golden Jubilee Medal of the IEEE CAS Society, the IEEE Millennium Medal 2000, the 2001 M.E. Van Valkenburg Award of the IEEE CAS Society, and was the 1st recipient of the IEEE CAS Society Vitold Belevitch Award in 2003. He received honorary doctorates from the University of Linkoping, Sweden, 1986, the Faculté Polytechnique de Mons, Belgium, 1988, Katholieke Universiteit Leuven, Belgium, 1988, the TU Budapest, 1995, the Poznan University of Technology, 2004, the University of Paderborn, 2011. He was member of multiple academies: the German Academy of Science and Engineering – acatech, the Rheinisch Westphälische Akademie der Wissenschaften (Germany), the Academia Europaea (London), the Academica Scientiarum et Artium Europaea (Salzburg/Vienna). He was a Life Fellow of IEEE, and member of EURASIP, ITG of VDE, Sigma Xi, Eta Kappa Nu, SITEL, and GAMM.
His name and fame is associated with passivity and losslessness properties, the theory of Kirchhoff circuits, electric filters, theory of communications systems, digital signal processing, wave digital filters, the Fettweis-Orchard theorem, multidimensional stability, robust numerical integration of partial differential equations, fundamentals at border of communications and physics.
Professor Fettweis is survived by his wife, Janie Piaskowski, 5 children (among whom Prof. Gerhard Fettweis, IEEE Fellow, TU Dresden, Germany, our prominent CAS member) and 16 grandchildren.