Otto Brune

Otto Brune

Otto Walter Heinrich Oscar Brune (10 January 1901– 1982) undertook some key investigations into network synthesis at the Massachusetts Institute of Technology (MIT) where he graduated in 1929. His doctoral thesis was supervised by Wilhelm Cauer (and Ernst Guillemin) who suggested that he provide a proof of the necessary and sufficient conditions for the realisability of multi-port impedances. Cauer himself had found a necessary condition but had failed to prove it to be sufficient. Brune coined the term "positive-real" (PR) for that class of analytic functions that are realisable as an electrical network using passive components. Brune also showed that if the case is limited to scalar PR functions then it is not necessary to allow ideal transformers (a limit to the usefulness of the theory) to be assured of a realisable network solution. The eponymous "Brune cycle" continued fractions were invented by Brune to facilitate this proof.