Background Traditional silicon-based Marx generators, limited by device physical limitations and leakage inductance in magnetically isolated drives, struggle to generate nanosecond-level fast pulses, particularly for applications requiring fast leading-edge pulses in plasma and other fields.
Objective To develop a fast leading-edge high-voltage pulse generator based on gallium nitride (GaN) power devices, overcoming the bottlenecks of traditional power supplies in response speed and isolation mechanisms.
Methods An improved modular Marx topology is proposed. The main circuit utilizes a common-mode inductor flux self-cancellation mechanism to achieve passive adaptive isolation. Simultaneously, a novel magnetically isolated synchronous drive circuit based on a totem-pole structure and capacitor compensation is designed to suppress the leading-edge delay caused by transformer leakage inductance.
Results A 7-level solid-state experimental prototype was built. Tests show that the drive voltage rise time is shortened to 9.3 ns; at a 1 kHz repetition rate, a stable high-voltage pulse with an amplitude of 1–4 kV and a pulse width of 200–1000 ns can be output; under 1 kΩ and 400 Ω loads, the pulse rise time reaches 5–6 ns and 8.2 ns, respectively. Furthermore, the total parasitic inductance of the main circuit and the parasitic capacitance on the load side are quantitatively extracted to be approximately 2.12 μH and 16.34 pF, respectively.
Conclusion This scheme has a simplified structure, strong scalability, effectively balances charge/discharge isolation and ultrafast synchronous drive, and possesses excellent nanosecond-level transient response performance, providing excellent hardware support for related cutting-edge applications.
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