A high-efficiency tunable relativistic magnetron with diffraction output

In this paper, a high-efficiency tunable relativistic magnetron with diffraction output (HTRMDO) is presented and studied numerically. To increase the tuning bandwidth and power efficiency, the outer radius of the resonant cavity and the magnetic field are simultaneously varied. The simulation results show that the HTRMDO has a tuning range between 1.280 and 2.430 GHz, corresponding to a tuning bandwidth of 62.0% with a center frequency of 1.855 GHz. In the tuning range, the maximum power efficiency is 71.9% and the minimum power efficiency is 36.0%, which complies with the 3 dB principle. Moreover, its output mode remains constant as TE31. This is a record tuning bandwidth and power efficiency for the continuously tunable relativistic magnetron.