Abstract
A high output power and high-efficiency {L} -band inverted relativistic magnetron (IRM) driven by a virtual cathode (VC) is proposed. By switching the configuration of cathode and anode, a greater magnitude of current could be generated from an external annular emission surface. In order to excite the desired mode more efficiently and enhance the mode stability, the emitting region is divided into eight azimuthally periodic parts. The prolonged VC is formed in the interaction region by dc electric field directly. The particle-in-cell (PIC) simulation demonstrates that the proposed IRM could generate an output a TM 01 mode with a microwave power of 1.97 GW for a diode voltage of 600 kV and a uniform guiding magnetic field of 0.18 T. Comparing with IRM with an emission surface inside the interaction region, the power conversion efficiency is improved from 18% to 86%.