Equivalent Circuit Method of Resonant System of Magnetron With Sector-and-Slot Resonant Cavities

In this paper, the equivalent capacitance and inductance of sector-and-slot resonant cavities are investigated theoretically by the equivalent circuit method. Thereby, the expression of the resonance frequency is obtained as a function of structure dimensions. In addition, the effects of structure dimensions on equivalent capacitance, inductance, and π-mode frequency are analyzed numerically, especially the slot width, slot length, and height. The results show that, compared with field theory, the equivalent circuit method is in more consistent with the simulation results, which verifies the validity of the equivalent circuit method. With the given structure dimensions, the equivalent capacitance increases with the increasing of slot length and height or the decreasing of slot width, while the equivalent inductance is opposite. Therefore, the change tendency of resonance frequency is determined by the relative changes of the capacitance, inductance, and coupling capacitance. This method can help to predesign and analyze resonant system of magnetrons with sector-and-slot resonant cavities efficiently.