Design and PIC Simulation of Dual-band RBWO Under Low Magnetic Field Operation

Abstract

A dual-band Relativistic Backward Wave Oscillator (RBWO) has been designed and simulated under the lowest magnetic field using a finite difference time domain (FDTD) based 3D electromagnetic code. The dual-band oscillations were obtained by cascading two slow-wave structures (SWS) with the same transverse dimensions separated by a drift section. To reflect the dual-band microwave of the backward TM01 mode into a forward TM01 wave towards the collector, a rectangular resonant reflector (RR) was used. The effect of cyclotron and Cerenkov absorption on the dual-band frequency generation and average RF output power was presented to identify the operating magnetic field. An average RF output power ∼275 MW was predicted at both ∼3.6 GHz and ∼4.5 GHz with a magnetic field of ∼0.25 T. © 2022 IEEE.