A Study on Semiconductor Switch Characteristics for a High Repetitive Fast Rising Solid-State Modulator

In this study, semiconductor switches are analyzed, compared, and selected for solid-state pulsed power modulators with a high repetitive fast rise time. Characteristics of discharge switches are critical in the design of pulsed power modulators with a fast rise time of several tens of nanoseconds. Five types of switches, including insulated gate bipolar transistor (IGBT) and silicon carbide metal–oxide–semiconductor field-effect transistor (SiC-MOSFET), were analyzed to select a discharge switch in addition to a comparison considering their rise time, arc reliability, and cost. A test circuit was designed and used to compare the rise time of semiconductor switches. Finally, a 1200-V/40-A IGBT was selected as the best performing discharge switch. The rise time and cost of the selected IGBT were up to 30% slower than and 1/6 those of the comparison SiC-MOSFET, respectively. The selected IGBT was employed in a high-voltage pulsed power modulator with specifications of 10 kV, 80 A, a maximum repetition rate of 50 kHz, and a minimum pulsewidth of 100 ns. The modulator exhibited a rise time of 18 ns or less and an operating repetition rate of 50 kHz. Finally, the fast rise time of the selected switch and its arc reliability was verified.