Solid state stepped transmission line transformer for spark gap triggering

Abstract

Spark gap switched transmission line pulse generators can achieve faster switching by overvolting the spark gap with high amplitude nanosecond pulses. A solid-state driven stepped transmission line transformer (TLT) is presented for triggering spark gaps in the overvoltage mode. The spark gap trigger source is simple and compact for integration with pulse generator systems. A totem pole MOSFET pulse source drives a four section discrete element TLT, each section stepped to three times the impedance of the previous stage. The line is designed with each section as 1/8 wavelength of the excitation pulse. The output pulse has a high transfer ratio of 6.9 into an open load, achieved in few step sections by driving the TLT with a low impedance source rather than a transmission line. Internal reflections are analyzed and timed to add constructively to form the output pulse.