Spatial-Harmonic Magnetrons with Cold Secondary-Emission Cathode: State-of-the-Art (Review)

Abstract

Spatial-harmonic magnetrons with cold secondary-emission cathode are efficient high-power sources throughout the millimeter wavelength band. In this paper, resent advances in design, modeling, and fabrication of such magnetrons are described. Low-voltage magnetrons, sub-THz tubes, and magnetrons with metamaterial anode structure are described to illustrate these advances. The issue of the lifetime of the magnetrons with a cold secondary-emission cathode is also addressed. The main problems related with the usage of an auxiliary cathode in such tubes are considered and alternative solutions are discussed. Potentials for further improving the performance of spatial-harmonic magnetrons are analyzed as well.