High-voltage nanosecond/subnanosecond pulse generators based on avalanche transistors

Pulsed-power technology is transitioning from military use to dual-use integration, and requirements have shifted toward higher output voltages, short rise times, high pulse-repetition frequencies (PRF), and compact, portable form factors. Because the switching device largely sets the attainable voltage, waveform fidelity, and PRF, device choice is decisive. Owing to their small size, simple drive, high-PRF capability, long lifetime, fast switching, low jitter, and ready availability, avalanche transistors (ATs) are increasingly favored. This review synthesizes methods for generating high-voltage nanosecond/subnanosecond pulses based on ATs. Generation schemes are organized as basic, composite, and pulse-stacking circuits, and their trade-offs are compared. Triggering challenges and failure mechanisms across topologies are analyzed, with emphasis on pre-stage conduction failure and current filamentation in M × N-stage Marx bank circuits. Mitigation strategies are summarized, including an auxiliary triggering topology and a triggering acceleration circuit. Representative applications are outlined—low-temperature plasma actuation, gas-switch triggering, biomedical uses, ultrawideband systems, and high-speed imaging—and prospective directions for avalanche-transistor pulse circuitry are discussed.