A Compact Gigawatt Pulsed Power Generator for High-Power Microwave Application

Abstract

Nanosecond square voltage pulse is of wide interest because of its potential military and industrial applications, such as high-power microwave (HPM). In this article, a gigawatt pulsed power generator (PPG) for HPM based on the multistage pulse forming networks (PFNs) with a voltage superposition using the Marx scheme, i.e., PFN-Marx generator, is proposed through the theory analysis, numerical simulation, processing manufacturing, and performance experiment. The PPG consists of the main subsystems of the primary power and pulse modulation subsystems. The primary power subsystem is a modular bipolar dc high-voltage generator based on the ac–dc–ac, high-frequency transformer, and voltage multipliers by using the power electronics switches. It can generate bipolar dc high voltage of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pm$</tex-math> </inline-formula> 42 kV to charge the PFN-Marx generator. As for the pulse modulation subsystem, the PFN-Marx technique is preferred, which consists of 24-stage and six <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{L}$</tex-math> </inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{C}$</tex-math> </inline-formula> sections. To verify the PPG, an experimental prototype is fabricated and tested. It has a characteristic impedance of about 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\boldsymbol\Omega$</tex-math> </inline-formula> and can deliver square voltage wave with an output voltage pulse of about 500 kV, full-width at half-maximum (FWHM) of 94 ns, and 10%–90% rise time of fewer than 35 ns, indicating its ability to deliver peak power beyond 6.25 GW. In addition, a transit-time oscillator was connected and can radiate microwave power of 0.8 GW at 12.89 GHz for the cathode voltage of 372 kV and the beam current of 9.3 kA.