The Research Of A Long Pulse Modulator Based On Anti-resonance Network And Transmission Line Pulse Transformer

High power pulsed technology has not only a popular trend towards high power,high repetition rate and minimization,but also a tendency to obtain high power pulse generators with long pulse,modularization and long lifetime.Traditional pulse forming network has the deficiency of overmuch network number,more susceptible to the stray parameters and etc.In this paper,an anti-resonance pulse forming network of a few networks has been theoretically explored and experimentally studied and a low loss transmission line transformer is designed to boost the voltage of the anti-resonance network.Hereby a long pulse modulator based on the three-section anti-resonance network and three-stage transmission line transformer is constructed.Experimental results provide verification that it is feasible to obtain long quasi-square pulses through using this project.The main work and results of this publication are listed below:1.Research on the anti-resonance pulse forming network.(1)Theoretical analysis about the circuit parameters of anti-resonance network outputting quasi-square pulses based on Kirchhoff’s law and Laplace transform.A method about calculating circuit parameters of this anti-resonance network is obtained.(2)A pulse forming network based on the two/three-section network has been established and tested.Experimental results show that two/three-section anti-resonance network can be used to generate high-quality quasi-square pulses.(3)Experimental stand with a four-stage Marx generator and single LC parallel resonance network is constructed and tested.Results show that anti-resonance network owns the property of modulating the LC series circuit to a quasi-square pulse.2.Construction of the transmission line transformer.(1)Suppress the waveform distortion and secondary line effects of the transmission line transformer.A low loss transmission line transformer without magnetic cores is designed.(2)Pulse step-up module based on two-stage transmission line transformer is developed and tested.The results display that this transmission line transformer can transmit a quasi-square pulse with the pulse width of 400 ns with no distortion and the voltage gain of this transformer achieve to 1.93.3.Research of single module of the long pulse modulator.A long pulse modulator system based on a three-section anti-resonance network and three-stage transmission line transformer is constructed.The output quasi-square pulse with its amplitude of 21.8 kV and pulse width of 400 ns on the 200Ω resistive load,the voltage gain of three-stage transmission line transformer achieve to 3,thus proving the feasibility of this project.4.Investigation of the long pulse modulator of modules connected in series.(1)The delay time,jitter and deviation of three electrodes gas spark switches are explored.The experimental results indicate that the delay time is about 2.47 μs;jitter between 10 ns to 20 ns and deviation less than 1%.The switches work stably and reliably.(2)A long pulse modulator system of modules connected in series is constructed and tested.Experiment of the superposition system based on two same modules connected in series is carried out.In the repetitive experiment,output voltage with the pulse width of 400 ns on the repetition rate of 10 Hz.The amplitude of the output pulse is double of that in single module.These results give the reliability of superposition of modules connected in series.However,the quality and amplitude of the output voltage of three module superposition system still remains to improve.