基于模块化Marx电路和传输线变压器的重频纳秒脉冲源设计

摘要

重频纳秒脉冲激励的大气压等离子体放电具有反应活性高等优点.设计了基于模块化雪崩三极管Marx电路和传输线变压器的重频纳秒脉冲源.计算不同Marx模块的导通时延和输出波形的抖动,研究了磁心数量、位置和形状对于输出波形的影响.磁心电感越大、外径与内径之比越大,且位于传输线变压器第一级和最高一级时对脉冲叠加效率的提升作用越明显.提出直接叠加和传输线变压器两种脉冲叠加方式组合的方法,进一步提高输出电压.整体脉冲源可以在50～300Ω负载产生2～14kV,高阻负载产生4～25kV,前沿3.8ns,脉宽7～15ns,重复频率0～10kHz的重频纳秒脉冲电压,装置结构紧凑,参数调节灵活,方便携带.%Atmospheric pressure plasma discharge excited by repetitive nanosecond pulsed voltage has high reactive ability.A repetitive nanosecond pulse generator was designed based on the modularized avalanche transistor Marx circuit and transmission line transformer (TLT).The delay time and jitter of output pulse waveform of different Marx modules were calculated.The impacts of magnetic cores quantity,position and dimension on the output pulse amplitude were analyzed.The pulse combination efficiency of TLT was remarkably improved by increasing the induction,increasing the ratio of outer diameter to inner diameter of magnetic cores and adopting magnetic cores on the first and top stages.Utilizing both the direct combination and TLT,the amplitude of output pulse was further improved.The generator can produce 2～14kV pulses into 50～300W resistive load and 4～25kV pulses into high impedance load,where the pulses have 3.8ns rise time,7～15ns pulse width and 0～ 10kHz repetitive frequency.The output parameters of the compact generator can be adjusted flexibly.