Theoretical Model, Experimental Survey, and Optimization of Pulse Parameters for 4H-SiC Drift Step Recovery Diode

The drift step recovery diode (DSRD) is one of the most popular superfast pulse power switches. The pulse parameter model of DSRD is important to improve the characteristics of the pulsed power system and reduce the complexity of the DSRD design. This article presents models for the prepulse amplitude, pulse front durations, and pulse peak based on the operating mechanism of 4H-SiC DSRD. The models establish the connection between the output pulse parameters with the DSRD structure and the material parameters. 4H-SiC DSRDs with different structures are designed for experiments, and the experimental results are consistent with the model predictions. Using the quantitative description of the pulse parameters from the proposed models, the optimization methodology is discussed to reduce the pulse front durations under the prepulse amplitude and peak pulse fixed. The accuracy of this optimization method is confirmed through simulations. The models developed in this article simplify the complex problem of nonlinear interactions involved in 4H-SiC DSRD optimization, enabling better utilization of 4H-SiC DSRD’s advantages in pulsed power systems.