Historical German Contributions to Physics and Applications of Electromagnetic Oscillations and Waves

The present review summarizes a series of the most important historical contributions of German scientific researchers and industrial companies in Germany to the physics and applications of electromagnetic oscillations and waves during the past 140 years and intends to point out some relations to Russian scientists. The chronology highlights the following scientists: Philipp Reis (*1834-†1874): first telephone; Hermann von Helmholtz (*1821-†1894): unification of different approaches to electrodynamics; Heinrich Hertz (*1857-†1894): fundamental experiments on electromagnetic waves; Karl Ferdinand Braun (*1850-†1918): crystal diode, cathode ray tube, transceiver with coupled resonance circuits; Christian Hülsmeyer (*1881-†1957): rudimentary form of RADAR; Robert von Lieben (*1878-†1913): triode as amplifier in transmitter; Heinrich Barkhausen (*1881†1956): Barkhausen-Kurz oscillations, first transit-time microwave tube; Manfred von Ardenne (*1907-†1997): first integrated vacuum tube circuits; Hans Erich Hollmann (*1899-†1961): multi-cavity magnetron, principle of reflex klystron; Oskar Heil (*1908-†1994): principle of the klystron, multi-stage depressed collector, patent of field effect transistor (FET); Walter Schottky (*1886-†1976): tetrode electron tube, theory of shot noise, Schottky effect, Schottky barrier; Herbert Kroemer (*1928): III-V semiconductor heterostructures; Jürgen Schneider (*1931): quantum electronic model of electron cyclotron resonance maser.