3-D simulation of 14 vanes 5.8 GHz magnetrons in non-uniform magnetic field

The suppression of the frequency spectrum noise is the key in the magnetron research. The performance of 14-vanes 5.8 GHz strapped magnetron is modeled, including cathode, vane, straps, pole pieces and output antenna. The cavity frequency is 5.86 GHz in the cold cavity simulation. Seven electron spokes confirm the mode works in the oscillation cavity region by the hot simulation. A non-uniform magnetic field distribution is calculated as a conic section curve by the pole structure in the model. When beam voltage is 4.5 kV, the anode current is 1.55 A and the axial value of the non-uniform magnetic field is 0.289 T, the output frequency 5.891 GHz and output power 4.9 kW in the hot test simulation are obtained. The efficiency of the electron interaction is 70.3%. The remarkable improvement in the frequency spectrum and the electron efficiency are achieved by suppressing the RF harmonic content.