Design and Simulation of Dual-Band Nonuniform Relativistic Backward Wave Oscillator Using a Bragg Structure as Its RF Circuit and Reflector-Cum-Mode Converter

A relativistic backward wave oscillator (RBWO) operating in dual (C and X) band is designed and studied using finite-difference time domain (FDTD) particle-in-cell (PIC) simulations implemented in MAGIC. It consists of a sinusoidally corrugated, moderately overmoded nonuniform slow wave structure (SWS) in the downstream section and a single fold two-way helically corrugated Bragg structure in the upstream section. A single intense relativistic electron beam (IREB) having ~5.1 kA of current is predicted for 600 kV of diode voltage. An RF output power ~720 MW in X-band and ~510 MW in C-band are predicted in TE₁₁ mode with a guiding magnetic field of ~2.5 T.