一种新的二维散射场远区时域信号实时获取方法  

An Improved Real-time Two-dimension Near-zone to Far-zone Transformation

作　　者：许锋[1] 洪伟[1] 

机构地区：[1]东南大学国家毫米波重点实验室,江苏南京210096

出　　处：《应用科学学报》2002年第3期254-257,共4页Journal of Applied Sciences

摘　　要：采用时域有限差分法求解散射问题时 ,时域信号的计算是在散射体近区内进行的 ,计算远区散射场通常有两种办法 ,一种是在频域内进行 ,另一种是在时域内进行 .由于二维时域 Green函数含有关于时间的积分 ,因而相对于三维问题 ,远区时域信号反而更难求解 .文中通过把等效激励源位置进行量化 ,综合排列激励时序 ,从而把所有激励源关于时间的积分转化为一个矩阵向量乘积运算 ,大幅度减少了计算时间 .同时 ,采用半解析的方法 ,精确地算出了其中的反常积分值 .最终 ,实时、快速和精确地获取了二维散射场远区时域信号 .Near zone to far zone transformation in the finite difference time domain (FDTD) method can be performed by the integral of the equivalent electric and magnetic currents originated from scattered electric and magnetic fields on a surface enclosing the object. There are two kinds of near zone to far zone transformation, one is in the frequency domain and the other is in time domain. Because the integral for time is included in the 2 D time domain Green function , the calculation of 2 D far zone time domain fields is more difficult than that of 3 D far zone time domain fields. However, by quantifying the positions of equivalent sources and arranging the time series, the calculations of the time integrals of equivalent sources are converted in to the calculation of matrix multiplying. Besides, by using the analytic method, the abnormal integral for the time is obtained accurately.

关 键 词：二维散射场 远区时域信号 时域有限差分法 二维时域Green函数 激励源位置量化 反常积分 信号获取方法 

分 类 号：TN011[电子电信—物理电子学]