Research On High-voltage High-frequency Subnanosecond Pulse Sourse Based On Switches Series-parallel Topology And Power Synthesis

In recent years,as a non-invasive treatment solution,subnanosecond pulse matching ultra-wideband antenna has broad application prospects in the treatment of brain diseases such as epilepsy,because of its excellent directivity and accurate handling.However,the regulation of neuronal action potentials by subnanosecond pulses is still at an exploratory stage.The performance of existing subnanosecond pulse generators are difficult to meet the needs of experimental research.As the basis for all research,developing a high-voltage high-frequency subnanosecond pulse generation with outstanding performance and flexible structure has become a top priority.The key research objectives and difficulties in this paper are how to ensure the pulse source output subnanosecond level pulse and how to increase the output subnanosecond pulse amplitude as much as possible.Based on this,the main research works and corresponding results obtained in this paper are as follows:First,the study shows that as the number of stages increases,the internal resistance of the avalanche transistor tends to decrease with increasing current flowing through the avalanche transistor.A step-by-step debugging of the avalanche-transistor-based Marx circuit demonstrates this suppose experimentally.That is,within the allowable range of Marx circuit flow capacity,appropriately increasing the number of Marx circuit stages is one of the effective ways to increase the output subnanosecond pulse amplitude of the avalanche transistor Marx circuit board.Next,based on avalanche transistor parallel structure,drawing on microstrip transmission theory,a 30-level Marx circuit with a parallel structure of two avalanche transistors was developed.The circuit PCB board outputs a pulse with adjustable voltage amplitude of 0.9?3.1k V,a 350-ps full width at half maximum,a 150-ps rise time,and an adjustable high-stability repetition rate of up to 10 k Hz,which shows that introducing the avalanche transistor parallel structure not only increases the current level of the entire circuit,but also further increase the output subnanosecond pulse amplitude of the avalanche transistor Marx circuit board.Then,based on avalanche transistor series-parallel structure,drawing on microstrip transmission theory,a 30-level Marx circuit with a four avalanche transistor series and parallel structure was developed.The circuit PCB board outputs a pulse with adjustable voltage amplitude of 4.5?7.0k V,a 370-ps full width at half maximum,a 170-ps rise time,and an adjustable high-stability repetition rate of up to 10 k Hz,which shows that introducing the avalanche transistor series-parallel structure can further substantially increase the output subnanosecond pulse amplitude of the avalanche transistor Marx circuit board.After that,the microstrip line power synthesizer was utilized in the design of the high-voltage high-frequency subnanosecond pulse generator for the first time,which further increase the output subnanosecond pulse amplitude of the high-voltage high-frequency subnanosecond pulse generator.Based on the theory of microstrip transmission circuit design and length adjustment of coaxial transmission line,it is feasible to synthesize simultaneous subnanosecond pulse.In this way,we overcome the obstacle of waveform distortion after power synthesis.Three microstrip line power synthesizers designed in this paper are available for amplitude synthesis of two road subnanosecond pulse,which have never been recorded in previous paper.Finally,based on the above research conclusions,a high-voltage high-frequency subnanosecond pulse source is developed,which can basically meet the parameter requirements of most existing experimental studies.The pulse source not only can output four-channel subnanosecond pulses with adjustable voltage amplitude of4.5?7.0k V,a 370-ps full width at half maximum,a 170-ps rise time,and an adjustable high-stability repetition rate of up to 10 k Hz,but also can output two-channel subnanosecond pulses with voltage amplitude of 6.7k V,a 560-ps full width at half maximum,a 280-ps rise time,and an adjustable high-stability repetition rate of up to 10 k Hz.What's more,the pulse source also can output a pulse with maximum voltage amplitude of 8.09 k V,a 470-ps full width at half maximum,a 360-ps rise time,and an adjustable high-stability repetition rate of up to 10 k Hz,which further verifies the correctness of the above conclusions.