All-solid-state Pulse Adder with Bipolar High Voltage Fast Narrow Pulses Output

A newly developed bipolar high voltage adder is proposed for generating fast narrow pulses. The new circuit topology enables the use of typical half-bridge semiconductor structures on the basis of conventional unipolar all-solid-state pulse adder. Magnetic ring transformers were employed for isolating the charge loop from the high-voltage pulse discharge loop, which simplified the isolation arrangement. Certain measures were implemented to resolve the EMI caused by the pulse adder arrangement. A laboratory prototype was assembled with 8 stages and each stage was made of 800 V MOSFETs. The modulator operating at 21 kHz repetition rate gives 2 kV bipolar pulses, with 200 ns positive/negative pulse widths, 37 ns rise time, 50 ns fall time, and 40 ns relaxation time into a 50 Omega resistive load. The adopted design is an all-solid-state approach with a simple control method, long maintenance-free lifetime, and high reliability.