Efficiency enhancement of a high power microwave generator based on a relativistic backward wave oscillator with a resonant reflector

A high power microwave generator based on a relativistic backward wave oscillator with a resonant reflector (BWO-RR) has been proposed in order to improve microwave conversion efficiency. In this device, the slow wave structure is separated by a modulation cavity, which significantly decreases the energy spread of the modulated beam electrons. At the end of the slow wave structure, an extraction cavity is employed to increase the beam-wave interaction and optimize the extraction of the output power. Particle-in-cell simulations show that a microwave efficiency of 46% has been obtained compared with that of 34% obtained with the BWO-RR.