基于SI-GaAs材料的新型脉冲压缩二极管

A novel pulse compression diode based on SI-GaAs material

针对快前沿高重频脉冲的应用需求,设计并研制了一种基于半绝缘砷化镓(SI-GaAs)材料的新型脉冲压缩二极管,通过实验对其压缩性能和重频运行能力进行了测试。实验结果表明,利用此开关能够将前级脉冲的上升沿压缩约270倍和脉宽压缩14倍;并在50Ω负载上,获得脉冲幅度1.3 kV、上升沿约1.6 ns、脉宽40.59 ns的电脉冲,重复频率达1 kHz,总计运行47 min,触发约两百万次。为研究脉冲压缩二极管的工作原理,对其静态伏安特性进行测试。分析认为,在电压初步加载阶段,SI-GaAs材料内的电场增强型的俘获与离化机制导致耐压增强,二极管在实验过程中出现延迟击穿现象;逆向偶极畴效应产生牵引机制,引发快速上升的位移电流,进而导致反偏结雪崩击穿,二极管表现出瞬间负阻特性,在负载上输出高压纳秒电脉冲。新型脉冲压缩二极管无外加触发快脉冲的前级器件,自身可以维持一定时间的强烈雪崩击穿状态,因此具有体积小、生产成本低的优点,可用于制作小型化高重频的纳秒脉冲功率源。

A novel pulse compression diode material was designed and developed based on semi-insulated gallium arsenide(SI-GaAs).A test circuit for its compression performance and repeat trigger performance was built.The results of the experiment show that,the rise time and pulse width of the input pulse can be compressed by approximately 270 times and 14 times,respectively,by using this switch.Besides,electrical pulses were obtained on a50Ωresistive load with 1.3 kV magnitude,1.6 ns rise time,and 40.59 ns width.It was realized to stably work under a repetitive frequency of 1 kHz and the time of operation was 47 minutes,i.e.,for a total of approximately two million triggers.To study the operation of the pulse compression diode,its static volt-ampere characteristics were tested.The analysis suggests that the electric field-enhanced capture and dissociation mechanism within the SI-GaAs material results in an enhanced withstand voltage at the beginning of voltage application.Therefore,the diode delayed breakdown during the experiment.The reverse dipole domain effect generates a traction mechanism that triggers a rapidly rising displacement current,which leads to an avalanche breakdown of the reverse bias junction.The diode then exhibits a transient negative resistance characteristic and a high voltage nanosecond electrical pulse is output on the load.The novel pulse compression diode does not require an additional pre-stage device to trigger fast pulses and can maintain a strong avalanche breakdown state by itself for a certain period of time.In summary,it has the advantages of small size and low cost,and it is an ideal switch for developing all-solid-state high repetition frequency nanosecond pulse generator.