High power microwave generation by a novel vircator with coaxial waveguide

A new configuration of a vircator is put forward for high power microwave generation. In this configuration, a coaxial waveguide and a hollow electric beam are used to enhance the beam-wave interaction and reduce the energy divergence of the injected electric beam in order to improve the microwave efficiency. A one-dimensional analytical model is used to describe the steady-state behavior of the electron beam and the virtual cathode, from which the space-charged limited current and the output microwave power are obtained. The preliminary 2.5-D particle-in-cell simulations using KARAT are carried out with typical electron-beam parameters of 550keV and 60kA, where pulsed microwave of 1.8GW in average power and 5.0GHz in the TM₀₂ mode is obtained. The power efficiency from the electron beam to microwaves is 4.8%.