Otto Julius Zobel

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Otto Julius Zobel (born October 20, 1887 in Ripon (Wisconsin) , † January 1970 in Morristown (New Jersey) ) was an American electrical engineer and made important work in the field of filter dimensioning at the beginning of communications technology .

Life

Filter for impedance matching from Zobel's patent specification

After Otto Julius Zobel received his bachelor's degree from Ripon College in Wisconsin in 1909, he received his master's degree in physics from the University of Wisconsin the following year . He stayed there until 1915 as a lecturer in physics. In 1914, Zobel obtained his Ph. D. with a dissertation on Thermal Conduction and Radiation . In 1915 and 1916 he taught physics at the University of Minnesota . In 1916 Zobel went to AT&T, where he worked on transmission technology, first in Maplewood (New Jersey) and from 1926 in New York City . In 1934 he went to Bell Telephone Laboratories , the research division of AT&T.

Otto Julius Zobel worked with George Ashley Campbell on frequency multiplexing on lines using single sideband modulation (SSB) and developed constant-k filters , M-derived filters , lattice filters and the Zobel network using the mirror impedance method .

Together with John R. Carson , he investigated noise , which mostly occurs as a disturbance in communications systems in order to separate it from the useful signal by means of a filter. In 1923 they both stated that this was not possible. In this thesis the term white noise was introduced, an expression for a noise signal which is spectrally constant. In later work on the Shannon-Hartley law it could also be shown that noise is a fundamental limitation in the so-called channel capacity .

Individual evidence

  1. ↑ Patent US1701552 : Distortion Compensator. Registered on June 26, 1924 , published on February 12, 1929 , applicant: AT&T, inventor: Otto J Zobel. ‌
  2. ^ John R. Carson, Otto Julius Zobel: Transient Oscillation in Electric Wave Filters . tape 2 . Bell System Technical Journal, July 1923, pp. 1 to 29 .
personal data
SURNAME Zobel, Otto Julius
BRIEF DESCRIPTION American electrical engineer
DATE OF BIRTH October 20, 1887
PLACE OF BIRTH Ripon, Wisconsin
DATE OF DEATH January 1970
Place of death Morristown, New Jersey