Efficiency study of a 2.2 kV, 1 ns, 1 MHz pulsed power generator based on a drift-step-recovery diode

Drift-step-recovery diodes (DSRDs) are used in pulsed-power generators to produce nanosecond-scale pulses with a rise rate of the order of 1 kV/ns. A 2.2 kV, 1 ns pulsed power circuit is presented. The circuit features a single prime switch that utilizes a low-voltage dc power supply to pump and pulse the DSRD in the forward and reverse directions. An additional low-current dc power supply is used to provide a voltage bias in order to balance the DSRD forward with respect to its reverse charge. The DSRD was connected in parallel to the load. In order to study the circuit's efficiency, it was operated over a wide range of operating parameters, including the main and bias source voltages, and the trigger duration of the prime switch. A peak voltage of 2.2 kV with a rise time of less than 1 ns and a rise rate of 3 kV/ns was obtained, where the efficiency was 24%. A higher efficiency of 52% was obtained when the circuit was optimized to an output peak voltage of 1.15 kV. The circuit was operated in single-shot mode as well as in bursts of up to 100 pulses at a repetition rate of 1 MHz. The experimental results are supported by a PSPICE simulation of the circuit. An analysis of the circuit input and output energies with respect to the MOSFET and DSRD losses is provided.