A dynamically tunable discrete-element transmission line pulse generator

Abstract

The Frozen Wave Generator (FWG) is a megawatt-class radio frequency pulse forming network that converts DC input up to ones-of-GHz center frequency (fc) by superposing an ensemble of alternately charged reactive storage elements. In this work, we demonstrate an all-solid-state, dynamically tunable, and chirp-capable FWG using the lumped-element transmission line (LETL) topology. A 12-segment LETL-FWG switched using a MOSFET is demonstrated and directly compared with a literature standard coaxial-based system. Comparison metrics for pulse width (tpulse) are studied as a function of the transmission line length and respective LC parameters. The chirp- and dynamic-tuning-capability as well as the high volumetric power density of the system are demonstrated by comparing the predicted and measured bandwidth, rise-time, pulse width, and delay-time from a 7.5 × 30 × 3 cm3 printed circuit board. The experiment resulted in dynamically tunable pulse trains with 15–24 ns pulse widths (40–80 MHz) and >35% conversion efficiency and an ∼80% reduction in volume compared to vacuum-relativistic pulsers in the same peak power class.