- Karl Küpfmüller
Karl Küpfmüller (
October 6 ,1897 –December 26 ,1977 ) was a German electrical engineer, who was prolific in the areas of communications technology, measurement and control engineering, acoustics, communication theory and theoretical electro-technology.He was born in
Nuremberg , where he studied at the Ohm-Polytechnikum. After returing from military service inWorld War I , he worked at the telegraph research division of the German Post in Berlin, and, from 1921, he was lead engineer at the central laboratory of Siemens & Halske AG in the same city.In 1928 he became full professor of general and theoretical electrical engineering at the "Technischen Hochschule" in
Danzig , and later held the same position in Berlin. In 1937 Küpfmüller was appointed as director of communication technology Research & Development at theSiemens -Wernerwerk for telegraphy. In 1941-1945 he was director of the central R&D division at Siemens & Halske.Later he was honorary professor at the "Technische Hochschule Berlin". In 1968, he received the
Werner-von-Siemens-Ring for his contributions to the theory oftelecommunication s and other electro-technology.He died at
Darmstadt .tudies in communication theory
About 1928 [K. Küpfmüller, "Über die Dynamik der selbsttätigen Verstärkungsregler", "Elektrische Nachrichtentechnik", vol. 5, no. 11, pp. 459-467, 1928. (German)
K. Küpfmüller, [http://ict.open.ac.uk/classics/2.pdf On the dynamics of automatic gain controllers] , "Elektrische Nachrichtentechnik", vol. 5, no. 11, pp. 459-467. (English translation) ] , he did the same analysis thatHarry Nyquist did, to show that not more than 2B independent pulses per second could be put through a channel of bandwidth B. He did this by quantifying the time-bandwidth product "k" of various communication signal types, and showing that "k" could never be less than 1/2. From his 1931 paper (rough translation from Swedish): [Karl Küpfmüller, "Utjämningsförlopp inom Telegraf- och Telefontekniken", ("Transients in telegraph and telephone engineering"), "Teknisk Tidskrift", no. 9 pp.153-160 and 10 pp.178-182, 1931. (Swedish) [http://runeberg.org/tektid/1931e/0157.html] [http://runeberg.org/tektid/1931e/0182.html] ]:"The time law allows comparison of the capacity of each transfer method with various known methods. On the other hand it indicates the limits that the development of technology must stay within. One interesting question for example is where the lower limit for "k" lies. The answer is acquired by at least one power change being needed to achieve one signal. So the frequency range must be at least so wide that the settling time becomes less than the duration of a signal, and from this comes "k"=1/2. So we can never get below this value, no matter how technology develops."
References
ee also
* Bissell, C.C. (2006) [http://www.ieeecss.org/PAB/csm/columns/June2006/June06Kupfmuller.pdf "Karl Küpfmüller, 1928: An early time-domain, closed-loop, stability criterion."] Historic Perspective. IEEE Control Systems Magazine, 26 (3). 115-116, 126. ISSN 0272-1708
* [http://www.tet.uni-hannover.de/kuepfmueller/Lebenslauf/lebenslauf.htm Kupfmüller biography at the University of Hannover] (German)Textbooks by Küpfmüller
* K. Küpfmüller, "Einführung in die theoretische Elektrotechnik" [Introduction to the theory of electrical engineering] . Berlin: Julius Springer, 1932.
* K. Küpfmüller (revised and extended by W. Mathis and A. Reibiger), "Theoretische Elektrotechnik: Eine Einführung" [Theory of electrical engineering: An introduction] , 17th ed. New York: Springer-Verlag, 2006.
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