Design of compact transmission line transformer for high voltage nanosecond pulses

The area of pulsed-power technology covers a broad range of voltages and pulse durations. State of the art systems have voltages up to a few hundred kilovolts at pulse lengths down to the nanosecond range. Special applications require extreme field strengths in the range of 1 GV/m. The design of a compact source meeting the above requirement aims for 1 MV, 1ns pulses. In this paper, we propose a concept for a novel compact transmission line transformer. To verify theoretical analyses and understanding, a model of the transmission line transformer has been simulated by time domain electromagnetic field solver. An optimized transmission line transformer has been built and first measurements have been performed. The equivalent simulation model agrees with the experimental results. The effect of secondary mode suppression by means of ferrite has been studied. Both simulations and experiments showed that ferromagnetic cores around each individual transmissions line in our design can be omitted.