Dmitri Apollinarievich Rozhansky (1.09.1882-27.09.1936) was a Soviet physicist and a corresponding member of the USSR Academy of Sciences (1933). He was born in Kiev. He graduated from St Petersburg University (1904). In 1911-21 he worked at the University of Kharkov (head of a department from 1914), in 1921—23 at the Nizhny Novgorod Radio Laboratory, in 1923 — 28 at the Central Radio Laboratory of the Weak-Current Plants Trust in Leningrad, from 1923 also at the Leningrad Physico-Technical Institute and from 1929 at the Electrophysical Institute. From 1923 he was professor at the Polytechnic Institute.
His main work was on electric discharges in gases, radiophysics and radar. He developed methods of oscillography of fast electrical processes (1910), of calculating the radiation of aerials (1922), and of measuring permittivity at microwave frequencies. He carried out studies of the propagation of short and ultrashort radio waves, taking into account the properties of the ionosphere and other factors, of the frequency stabilisation of valve oscillators, of the physics of gas discharge, of microwave electronics and of aerial theory. Work was done under his direction on the creation of short-wave transmitters and pulse radars. He put forward the idea of the drift klystron.
The first period in the history of Russian radiophysics and radio engineering is associated with Rozhansky's name. He founded a school of radiophysicists (Yu. B. Kobzarev, A. A. Slutskin, D. S. Shteinberg and others).