Circuit-Level Transient Simulation Study of Recovery Characteristics in a Parallel-Resonator-Assisted GaN SBD Limiter

In this work, fast-recovery characteristics of high-power GaN Schottky barrier diode (SBD) limiters are investigated through a parallel-resonator-assisted topology and a circuit-level transient simulation method for recovery-process analysis. By introducing a parallel resonant unit, composed of the diode junction capacitance and short-circuited stubs, into a conventional shunt limiter topology, the high-frequency passband characteristics of the traditional shunt topology under large-size GaN SBD conditions are improved, and the transient response after high-power excitation is reshaped, thereby shortening the recovery time from the large-signal limiting state to the small-signal steady-state operation. Based on the ADS platform, a combined excitation scheme using a high-power pulse signal and a low-power continuous-wave signal is adopted to perform circuit-level transient simulation of the limiter recovery process. Simulation results show that, under a 50-W input power condition, the recovery time is reduced from 16.3 ns to 11.2 ns after introducing the parallel resonant unit in the C-band. These results indicate that circuit topology significantly affects the recovery behavior of high-power GaN SBD limiters, and the proposed approach provides a useful reference for circuit-level design and transient analysis of fast-recovery microwave limiters.