High-Voltage Repetitive Nanosecond Pulse Generator Utilizing Power Synthesis of Modified Avalanche Transistorized Marx Circuits

In order to further improve the output voltage amplitude and repetitive operation reliability of nanosecond pulse generator (PG) based on avalanche transistor (AT), the method of power synthesis of modularized Marx circuits with transmission line transformer (TLT) is employed in this article. The modified positive 4 x 11-stage Marx circuit introducing base-triggering method is designed and implemented to improve the operation reliability. The triggering synchronization and the consistence of output characteristics of multipleMarx modules with an identical trigger pulse are validated. The feasibility of combining pulses generated from four Marx modules with an optimized four-stage TLT is demonstrated. The influences of the type and quantity of magnetic core and the superimposed stage number of TLT on the output performance of the generator are investigated. The operation characteristics of the generator including output parameters, trigger time-delay, and loop efficiency in the whole working range are evaluated. The experimental results show that the working range of the overall device has been widened significantly with the injection of additional initial carrier. Accordingly, the generator prototype is capable of achieving the output performance with an adjustable voltage amplitude in the range of 7.8-26.7 kV on a matched 300-Omega resistive load and 12.2-38.9 kV on the high-resistance load, respectively, a 10%-90% rise time of 3.6 ns, and a full-width at half-maximum (FWHM) of 12.2 ns. A long-term test with the maximum repetition rate of 3 kHz is conducted to realize high-voltage output and high-frequency operation simultaneously.