基于双向射线追踪的损耗介质目标散射计算  

Extended bi-directional analytical ray tracing algorithm for lossy dielectric object

作　　者：郑浩[1] 叶红霞[1] 徐丰[1] 

机构地区：[1]复旦大学电磁波信息教育部重点实验室,上海200433

出　　处：《电波科学学报》2015年第5期896-902,共7页Chinese Journal of Radio Science

基　　金：国家自然科学基金(No.61001007);教育部科技支撑基金

摘　　要：双向解析射线追踪(Bi-directional Analytical Ray Tracing,BART)算法从发射端和接收端同时追踪电磁波射线在导体表面的弹跳过程,并用解析的三角形表征射线束的横向尺寸,极大地提高了电大尺寸导体目标的电磁散射计算速度.将此算法进一步推广,发展了扩展型双向解析射线追踪(Extended BART,E-BART)算法,并应用于电大尺寸、有耗介质目标的高频电磁散射计算.针对介质面元,E-BART算法需同时考虑反射射线和透射射线的追踪过程,并计算物理光学(Physical Optics,PO)和几何光学(Geometry Optics,GO)散射参数.损耗介质的射线传播过程满足复Snell定理,传播方向由等相面确定,衰减方向由等幅面确定.考虑到损耗介质内部的格林函数与空气的格林函数不一致,提出了PO/GO近似变换的思想来计算相应的散射场.与商业FEKO软件的计算结果对比,证明了E-BART算法的准确性和高效性,并分析了几种典型目标的散射特性.Bi-directional analytical ray tracing（BART）was presented for calculating the scattering from conductive targets with electrically large size.In BART,the electromagnetic（EM）rays were assumed to be shot from both the sender and the receiver,and the bouncing on the conductive faces was traced.To speed up the tracing progress,the EM ray beams were expressed as analytical triangles,which could be calculated by triangle operations.In this paper,the extended BART（E-BART）is extended to calculate the radar cross section（RCS）of the lossy dielectric objects with electrically large size.In E-BART,both the reflected and the refracted rays should be taken into consideration on the lossy dielectric surfaces.The complex Snell-Descartes and Fresnel laws of lossy dielectric media indicate that the direction of wave propagation is determined by the equal-phase plane and the attenuation is calculated along the direction of equal-amplitude plane.In addition,the PO/GO transformation matrix is derived to modify the Greenfunction from dielectric media to free space.Compared with the FEKO software,EBART is proved to be accurate and effective.

关 键 词：射线追踪 损耗介质 高频电磁计算 

分 类 号：TN011[电子电信—物理电子学] TM152[电气工程—电工理论与新技术]