A Dual-Frequency High-Power Microwave Generator

We propose a novel dual-frequency high-power microwave generator consisting of both an axial generator and a radial one stretching from the middle of the tube head of the former. As a high-voltage pulse is injected into the diode system, a cathode with two blades generates two relativistic electron beams that separately travel through the axial and radial diodes. Therefore, both the subsources are driven by the relativistic beams and generate intense microwave pulses simultaneously. An axial relativistic backward-wave oscillator and a radial transit-time oscillator are designed and combined to realize this purpose. Particle-in-cell simulation shows that when the diode voltage is 505 kV, microwaves with powers of 0.95 and 1 GW are generated in the axial and radial subsources, with frequencies of 15.2 and 9.5 GHz, respectively. An equivalent efficiency of over 35% is achieved with an axial magnetic field of 0.86 T and a radial magnetic field of 0.5 T.