加权总场法在PSTD算法中的应用

Application of Weighted-total-fields technique in the PSTD Algorithm

伪谱时域 (PSTD)方法可以处理电大尺寸目标电磁散射问题。本文介绍了一种能够把入射波有效引入PSTD计算区域的新方法———加权总场法。该方法通过引入类似于FDTD中连接边界的连接层 ,将计算区域划分为总场区、连接区和散射场区。为了总场区和散射场区的连续 ,在连接区引入窗函数 ,通过设置 8 10层连接区就可以将入射波有效地引入到PSTD总场区。这样使入射波和目标分离 ,实现了复杂目标的单独建模 ,从而使PSTD便于模拟复杂目标的电磁散射。文中以高斯脉冲为入射波 ,通过二维情况下目标散射宽度的数值结果 。

The Pseudospectral time-domain (PSTD) algorithm can be used to solve the scatte ring of the electrically large objects. To introduce an incident fields into the PSTD computed region, a weighted-total-fields technique is presented in this pa per. Similar to the FDTD method, the PSTD computed region is divided into the to tal-filed zone, scattering-field zone and connection zone. A scalar weighting f unction is employed to let the incident field varying from 0 to 1 in the 8-10- layer connecting region. It is much easier for the PSTD to simulate scattering o f complex objects by using the weighted-total-fields technique than applying t he pure scattered-fields scheme. The validity of the presented method is proven from numerical results of scattering width of two objects illuminated by a Gaus s pulse, respectively.