The Development Of High-voltage Pulse Modulator Power

Magnetron, the core of microwave generator, converts DC energy to microwave energy. Magnetron requires that its power supply has small size, small ripple and good stability. High-voltage pulse modulation acts as microwave generator's energy provider and its role acts as the person's heart. Microwave generator requires high stability, low noise and good spectrum characteristics etc, and raises higher requirement for high-voltage pulsed modulation power. Through simulation optimize specific circuit parameters to make up for the shortage of modulating tube's performance, this paper developed 400kHz repetitive frequency of pulse modulation, also applied planar transformer to high power field and made the most important step for the miniaturization of high voltage power supply.This paper is divided into high-voltage power supply and pulse modulation. High-voltage power supply firstly starts from the working principle of half-bridge topology and linear regulator topology, and separately introduces the related design included positive gate output, negative gate output, filament voltage output, feedback loop, offset power supply, filament shift and negative gate testing part; Pspice simulation is adopt to analyze that the distribution of high voltage transformer parameters have an affect on the performance of the waveform, then the mathematical modeling analysis of distributed capacitance is established, and two layers and 4 layers PCB technology are used to draw primary coil and secondary coil, finally achieves the optimized performance's purpose of high voltage power supply. Pulse modulation circuit adopts the isolated transformer to drive modulation tube, then begins from driving dead time and the changs of winding process to reduce the leaking inductance of isolated transformer, then respectively simulates and analyzes six aspects included the dead time, the isolated transformer's leaking inductance, leakage-inductance absorbed resistance, drive optimization, the tubes'series resistance and modulating tube, and compares the different circuit parameters's impact on the modulation circuit performance, gradually optimizes and determines the modulation circuit's parameters, finally achieved the design requirements.