三极管开关型Marx脉冲成形电路的改进

Improvement on Marx Type Pulse Circuits Using Bipolar Junction Transistors as Switches

介绍了三极管进入雪崩状态的3种方式,分析了采用三极管的脉冲电路的工作机理,研究了三极管做开关的Marx电路中限流电阻在电路中的作用,以及对电路造成的损耗问题及其对输出脉冲电压的影响,采用降低电阻的隔离电压和二极管代替部分电阻的方法提高脉冲电源的输出峰值.通过实验对比了不同方案的十级脉冲发生器的输出,结果表明,改进后的发生器输出脉冲电压幅值更高,二极管代替限流电阻方案的输出脉冲前沿更快,输入功率减小,输出功率增大,发生器的工作效率提高.

The bipolar junction transistor（BJT）is widely used in pulse generators for the advantages of high switching speed and high repetitive frequency.The ways for BJT performing in avalanche mode were introduced,and the working mechanism of a pulse circuit using BJT was analyzed.In the Marx circuit based on BJTs,the functions of current-limiting resistors,the circuit loss due to resistors and their influence on the magnitude of output pulse were analyzed theoretically and experimentally.The improvements using diodes to replace current-limiting resistors and using traditional Marx structure were proposed.The output pulses of four negative Marx pulse generators with 10-stage in different schemes were compared.It is shown that,the improved circuits have higher pulse magnitude,and the last circuit is the best method whose fall time is shortest and magnitude is highest.Furthermore,the output power increases but the input power decreases.The efficiency of the whole generator is improved.