Design and simulation of a π/2-mode spatial-harmonic magnetron

Design and 3D numerical simulations of a 37.5 GHz spatial-harmonic magnetron (SHM) are presented. The effect of geometrical parameters of the side resonators of the anode block on output power are considered using the results of a theory based on the single harmonic approximation approach. This theory enables determination of the optimum geometrical parameters of the side resonators. SHM design evaluation is carried out via numerical simulations performed with a 3D particle-in-cell (PIC) code embedded in CST-Particle Studio. Effect of varying the external quality factor and DC-anode voltage on output power, efficiency and stability of operation are also considered. The presented SHM shows stable operation in the π/2-mode over a range of DC anode voltages extending from 12.4 kV to 13 kV and for an axial magnetic flux density equal to 0.53 T. RF output power of the SHM varies from 25 kW to 47 kW over these voltages with a maximum efficiency of around 18.5%.