Alfred Leo Maria Fettweis (27 November 1926 â 20 August 2015) was a Belgian-born German engineering scientist and communications engineer. He is regarded as the inventor of the wave digital filter. He was professor of communication engineering at Ruhr University Bochum and a founding member of its Faculty of Electrical Engineering and Information Technology. Fettweis was elected to several academies, including the North Rhine-Westphalian Academy of Sciences, Humanities and the Arts, the Academia Europaea, the European Academy of Sciences and Arts and acatech, and was a Life Fellow of the IEEE.
Alfred Fettweis was born in 1926 in Eupen, Belgium. He was the second of three children of the agricultural engineer Paul Fettweis (1886âÂÂ1964) and his wife Helene, née Hermanns, who worked as a pharmacy assistant. He was a grandson of the Eupen dye works owner Leo Fettweis (1841âÂÂ1922) and a nephew of the mathematician Ewald Fettweis.
In 1942 Fettweis was conscripted as a Luftwaffe auxiliary (Flakhelfer) in Aachen. While on military service he volunteered for a special course in high-frequency engineering held from October 1943 at the Daaden military training area (Lager Stegskopf) and from November 1944 served as equipment technician at the air base in Stade and later at the airfield in Jagel near Schleswig. In January 1945 he was sent for further training to Halle. As the front approached he made his way via Berlin to Lübeck, where he was taken prisoner of war by British forces. He was held until September 1945 near Eutin and then in Vilvoorde, and was released in November 1945.
From 1946 to 1951 Fettweis studied electrical engineering at the Université catholique de Louvain (UCLouvain) in Leuven, and later at Columbia University and the Polytechnic Institute of Brooklyn in New York. After graduating as Ingénieur civil électricien, he worked from 1951 to 1963 as a development engineer for ITT Corporation in Antwerp and, from 1954 to 1956, in the United States. In 1963 he obtained the degree of Docteur en sciences appliquées at UCLouvain.
Also in 1963 he was appointed professor of theoretical electrical engineering at the Technical University of Eindhoven in the Netherlands. In 1967 he was appointed full professor (Ordinarius) of communication engineering at the newly founded Ruhr University Bochum, where he built up a new chair and became one of the founding figures of the Faculty of Electrical Engineering and Information Technology. He retired in 1992.
In 1975 Fettweis became an ordinary member of the North Rhine-Westphalian Academy of Sciences, Humanities and the Arts. He was also a Life Fellow of the IEEE in New York, a member of the Academia Europaea in London (from 1992), of the European Academy of Sciences and Arts in Salzburg (from 1992), and of the German Academy of Science and Engineering in Munich (member of its predecessor Convent from 1997, acatech from 2002, DATW from 2008). He was a member of the Catholic guild Gilde Alfred Delp within the Cartell Rupert Mayer.
His teaching and research focused on circuit theory, systems theory, digital signal processing, wave digital filters, numerical integration of partial differential equations, and on relationships between communication engineering and fundamental questions in physics.
His son is the communications engineer Gerhard Fettweis.