Solid-state power switches for HPM modulators

Abstract

Power modulators for pulsed microwave applications, generally utilizing a thyratron-switched PFN, typically produce 50-120 kV, 1-2 kA microsecond timescale pulses with sub-microsecond (/spl sim/100-200 nsec) risetimes. This paper reviews an investigation into the feasibility of utilizing certain solid-state power switches at the relatively fast speeds required for HPM modulators. Different thyristor switches, an ABB HCT and an n-type MCT, were investigated in a fast (/spl sim/136 nsec), low-impedance 1.4-/spl mu/sec PFN. Limited success was obtained, as both switches demonstrated sub-microsecond switching times. The ABB HCT switching a bias of 944 V in 220 nsec. These results indicate that thyristor switches may be fast enough for some HPM modulator applications.