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

This paper discusses design procedure and 3-D numerical simulation of a 140 GHz spatial-harmonic magnetron (SHM). The well known scaling laws and an approximate approach based on single harmonic analysis are used to determine the interaction space dimensions and the optimum geometrical parameters of the side resonators. Numerical simulations of the SHM were performed using CST-Particle Studio. Since the simulations are not based on artificial RF priming or assuming restrictive assumptions on the mode of operation or on the number of harmonics to be considered, electromagnetic oscillations grow naturally from noise. 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. Output power of the SHM varies from 2 kW to 11 kW over these voltages with a maximum efficiency of about 6.8%.