FDTD方法分析高功率微波对大气的电离与击穿

 应用麦克斯韦方程和电子流体方程，利用时域有限差分方法(FDTD)计算模拟了高功率微波(HPM)对大气的电离与击穿；该方法用瞬时电场代替等效电场，时刻更新大气电离击穿过程中的电离频率和碰撞频率，消除了近似解析法未考虑大气电离击穿过程中电场幅度衰减而引起的误差，计算得到击穿阈值大小随海拔高度的变化趋势与文献所得的变化趋势相吻合，其值略大于近似解析解；并通过仿真计算分析了HPM脉冲幅值、脉宽以及海拔高度等参数对大气击穿的影响。

FDTD computation of air ionization and breakdown caused by high power microwave

Combing Maxwell equations and electron liquid equations, air ionization and breakdown caused by high power microwave(HPM) are analyzed using FDTD method. Comparing with the traditional approximate analysis, this method uses instantaneous electric field instead of equivalent electric field, and updates ionization frequency and collision frequency in each time step, so it can eliminate the error of analysis methods, which ignore the attenuation of electric amplitude during atmosphere breakdown. The change tendency of computed air breakdown threshold with altitude matches well with those in references, while the threshold values are a little larger. Finally, the impact of HPM amplitude, pulse width and altitude on air breakdown threshold are analyzed using this method.