利用两次傅里叶变换得到半空间界面的反射波后,将直接入射波和界面反射波两个时域脉冲源通过等效原理引入到包含目标的时域有限差分(FDTD)的计算域中.计算了高功率微波入射情形下,改变入射面、极化方式时天线罩内部观察点的能流密度的变化,并总结其规律.数值算例表明,对于贴近地面的目标来讲,半空间的反射波会给目标内部带来新的能量冲击.该方法可以用于计算目标内部耦合近场及功率密度.

In this paper,the reflected wave of a lossy half space is computed by using the combination of Fourier transform and Fresnel formula,and it is introduced to finite difference time domain method (FDTD) calculation region by Equivalence Principle.The results by different incident planes and polarization modes are discussed.The numerical results show that the reflected wave would lead a second time energy burst when the target is located near ground.This method can be applied to computation of near field and coupling energy inside of the target.The effect of half space is not considered in existing study,this method has a basic significance of half space effect analysis for the electronic systems under HPM environment.