A Nanosecond Pulse Generator Based on the Combination of Avalanche Transistor Marx Circuit and Transmission Line Transformer

Abstract

The method of generating atmospheric pressure plasma is usually to apply pulses with an amplitude of kV level, ns/sub-ns level rise time and pulse width, and kHz repetitive rate, especially the pulse rise time and width should be as small as possible. As a mature commercial device, the avalanche transistor has the advantages of fast switching speed, small size, and long life. It is widely used in the design of nanosecond or sub-nanosecond pulse generators. The breakdown voltage of a single avalanche transistor is about 300V. The Marx circuit can achieve high voltage amplitude output. Here, In order to further increase the voltage, a combining topology using the combination of avalanche transistor-based Marx circuit and transmission line transformer (TLT) was adopted to obtain a high-voltage nanosecond pulse with an amplitude of 10kV, a rising time of ~650ps, and a full width at half maximum (FWHM) of ~3ns on a 200Ω load.