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.