Experimental Demonstration of a Compact, High Average Power, Pulsed Power Driver for Printed-Circuit Board Nonlinear Transmission Lines

Nonlinear transmission lines (NLTLs) are a promising technology for high power microwave (HPM) generation. However, NLTLs are also typically characterized by relatively short RF pulse widths, on the order of tens to hundreds of nanoseconds. One approach to increasing the overall average microwave power is the application of short excitations in very high pulse repetition frequency, thus yielding a high effective RF duty cycle. This research details the development of a compact pulsed power driver capable of delivering up to 3 kV high voltage excitation, with pulsed widths between 100 – 500 ns, and multi-MHz pulse repetition frequency to a PCB-based NLTL HPM source.

I. Introduction

Nonlinear transmission lines (NLTLs) are a unique type of high power microwave (HPM) source that are able to produce short, high power radiofrequency (RF)-to-microwave frequency bursts from a unipolar excitation. Unlike vacuum-based HPM sources, microwave production in NLTLs does not rely on an electron beam freely propagating in vacuum [1]. Instead microwave production is achieved via some combination of nonlinearity, dispersion, and material dipole motion [1]. Various sub-types of NLTLs exist, which employ nonlinearities in dielectric and magnetic materials, as well as semiconductors [2]. Notably, NLTLs utilizing nonlinear magnetic materials generally feature superior characteristics at higher GHz to multi-GHz frequencies (e.g. [3]), which motivates their interest here.