DESIGN AND 3-D PARTICLE-IN-CELL SIMULATION OF A 140 GHz SPATIAL-HARMONIC MAGNETRON

Design and 3-D numerical simulation of a 140 GHz spatialharmonic magnetron (SHM) are presented. The effect of geometrical parameters of the side resonators of the anode block on the output power are considered using the results of a theory based on a single harmonic approximation approach. This theory enables the determination of the optimum geometrical parameters of the side resonators. SHM design evaluation is carried out via numerical simulations performed with a 3-D particle-in-cell (PIC) code embedded in CST-Particle Studio. Simulations of the SHM are performed without artificial RF priming and without assuming restrictive assumptions on the mode of operation or on the number of harmonics to be considered. Thus in our simulations the electromagnetic oscillations grow naturally from noise. The results of time evolved electron flow simulations and gradual formation of a single frequency RF oscillation are presented. The presented SHM shows stable operation in the π /2-1-mode at 140 GHz over a range of DC anode voltages extending from 11.3 kV to 11.5 kV and for an axial magnetic flux density equal to 0.79 T. RF Output power of the SHM varies from 2 kW to 11 kW over these voltages with a maximum efficiency of around 6.8%.