A Novel Coaxial Relativistic Backward-Wave Oscillator for Millimeter Wave Generation

A novel coaxial relativistic backward-wave oscillator (C-RBWO) for millimeter wave generation is proposed and studied by simulation. In the proposed C-RBWO, a coaxial structure is used in the beam-wave interaction region. According to the dispersion relations in the slow-wave structure region, a new simple and effective reflector is designed for effective cutoff the backward-wave at the electron-injector end. Nonuniform corrugation depth is used to increase the efficiency. For an electron beam with 263-kV voltage and 610-MW power, about 80-MW output power is obtained by simulation at 96.2 GHz. The C-RBWO operates at a low magnetic field (3.7 T) below the cyclotron resonance value (about 10.2 T). The output efficiency is beyond 13%.