影响高功率光导开关临界频率热因素的数值分析

Numerical simulation on factors affecting critical frequency of high-power photoconductive semiconductor switch

基于时域有限差分法(FDTD)对非线性模式面结构砷化镓光导开关的热传导过程进行了数值模拟。研究了光导开关临界频率与电流丝位置、半径、数量、芯片尺寸、环境温度等参数的关系。研究表明:临界频率随电流丝半径、数量的增加,呈指数上升趋势;临界频率随着电流丝深度、芯片厚度的增加,呈指数下降趋势;临界频率在一定范围内随环境温度的增加呈线性下降趋势。

The heat dissipation process of GaAs photoconductive semiconductor switch（PCSS） in nonlinear mode has been simulated based on finite difference time domain method（FDTD）.Factors affecting the critical frequency,such as location,radius,number of current filament,dimensions of PCSS chip and environment temperature were discussed.The results are as follows： the critical frequency exponentially increases as radius and the number of current filament increases,it decreases exponentially as distance between location of current filament and surface of chip increases and thickness of chip increases.The critical frequency decreases linearly as environment temperature rises in a special range.