Karl Willy Wagner (1883–1953) was a German pioneer in the theory of electronic filters. He is noted by Hendrik Bode as being one of two Germans whose;
. . . important contributions were slow to diffuse outside Germany because of the accidental intervention of World Wars I and II.
The other German being referred to is Wilhelm Cauer. Wagner was the second referee on Cauer's milestone 1926 thesis but Wagner fell out with Cauer in 1942 after he refused to support Wagner's research proposals with the German Society of Electrical Engineers (Verband der Elektrotechnik - the VDE).
Wagner was removed from office in 1936 because he refused to dismiss his Jewish employees.
^Bode, H W, Network Analysis and Feedback Amplifier Design, Robert E Krieger Publishing, 1975.
^Cauer, W, "Die Verwirklichung der Wechselstromwiderstände vorgeschriebener Frequenzabhängigkeit" ("The realisation of impedances of specified frequency dependence"), Archiv für Elektrotechnic, vol 17, pp355-388, 1926.
^E. Cauer, W. Mathis, and R. Pauli, "Life and Work of Wilhelm Cauer (1900–1945)", Proceedings of the Fourteenth International Symposium of Mathematical Theory of Networks and Systems (MTNS2000), Perpignan, June, 2000. Retrieved online 19 September 2008.