An $L$ -Band Relativistic Magnetron With Cathode Priming

An L-band relativistic magnetron (RM) that adopts stepped-mode conversion diffraction output (DO) is presented and investigated by the 3-D particle-in-cell simulations. The cathode priming technique is introduced to quicken startup of the π-mode and suppress unexpected modes during startup. The length and width of the emission region, the deviation angle between the emission region and the anode vane, and the extended length of the cathode are four important parameters for cathode emission. The simulation results indicate that these four parameters have significant impact on the performance of the RM with DO (MDO). With fixed voltage and magnetic field, all these four parameters have the optimum values which lead to the highest power efficiency. Typical simulation results are as follows: when the applied voltage and magnetic field are 520 kV and 0.3 T, respectively, the L-band A6 MDO radiates microwave of 2.19 GW at 1.577 GHz, and the corresponding power efficiency is 61%.