Karl Küpfmüller
Encyclopedia
Karl Küpfmüller 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 returning from military service in World 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 the Siemens
-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 of telecommunication
s and other electro-technology.
He died at Darmstadt
.
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):
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
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
Nuremberg
Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...
, where he studied at the Ohm-Polytechnikum. After returning from military service in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, 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
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
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 the Siemens
Siemens
Siemens may refer toSiemens, a German family name carried by generations of telecommunications industrialists, including:* Werner von Siemens , inventor, founder of Siemens AG...
-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 of telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s and other electro-technology.
He died at Darmstadt
Darmstadt
Darmstadt is a city in the Bundesland of Hesse in Germany, located in the southern part of the Rhine Main Area.The sandy soils in the Darmstadt area, ill-suited for agriculture in times before industrial fertilisation, prevented any larger settlement from developing, until the city became the seat...
.
Studies in communication theory
About 1928, he did the same analysis that Harry NyquistHarry Nyquist
Harry Nyquist was an important contributor to information theory.-Personal life:...
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):
- "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."
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.
Further reading
- Bissell, C.C. (2006) 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
- Kupfmüller biography at the University of Hannover (German)