The moment method is used to calculate the rcs of three - dimensional targets in this paper . these targets include conducting targets , dielectric targets and coat targets . triangular patches are used to model the surface of the target , then electric field integral equation ( efie ) and magnetic field integral equation ( mfie ) are built which satisfy the boundary conditions . the rwg vector base functions are used to denote equivalent electric current and magnetic current on the surface of the target . finally use the galerkin method ( rwg vector base functions are basis function and test function ) to transform integral equations into matrix equation . when obtain the equivalent electric current and magnetic current , we can calculate the scattering field and the rcs of the target 本文利用矩量法计算了三维导体目标、介质目标、涂层目标的雷达散射截面。首先采用三角形面元对物体表面几何形状进行模拟，然后建立满足边界条件的电场积分方程( efie )和磁场积分方程( mfie ) ，将物体表面的等效电磁流用rwg矢量基函数表示，最后利用伽略金法( rwg矢量基函数既作为基函数又作为检验函数)将电磁场积分方程转化为矩阵方程求解未知电磁流系数，得到了表面的等效电磁流后，可以计算散射场和目标的雷达散射截面。
As one part of the work , the induced current on perfect conductor surface is computed with mom method and graphed by origin . the factors , such as choice of basis function and sliced mounts of one cell , which affect solution accuracy are summarized . all of these provide a good basis for the latter computation of array scattering field 其中第一部分工作从电场积分方程出发，利用矩量法计算了理想导体贴片上的感应电流，进而得到平面阵列和曲面阵列的散射场，研究了阵列单元尺寸、排布形式和入射波的角度，以及曲面阵列的阵面形状等因素对阵列散射场的影响规律。
This technique combines the edge - based finite - element method with physical optics ( po ) and physical theory of diffraction ( ptd ) . the hybrid technique is applied to compute the scattering fields from the electrically large bodies with cracks and cavities on their surfaces . it is also used to analyze the scattering characteristics of microstrip antennas residing in a cavity mounted on metal objects with finite sizes 本文采用edge - basedfem为基本方法，结合物理光学法( po ) 、物理绕射理论( ptd ) 、边界积分方程( bi ) 、区域分解技术( ddm )和完全匹配层( pml )吸收边界条件等求解方法构成的混合方法，对电磁散射和辐射问题进行了研究，主要包括以下内容：提出了一种edge - basedfem与物理光学方法和物理绕射理论相结合的混合方法? fem po - ptd方法，并将该混合方法应用于带有腔体或槽缝的电大尺寸导体目标的电磁散射特性分析和位于有限导体目标上的背腔式微带贴片天线的电磁散射特性分析。
The backward scattering field of extended target is approximated as the synthesis of many strong scatter centers on target , and geometric optical method is used in establishing deterministic model of a aircraft in the paper , the model is used to evaluate the performance of frequency diversity in suppressing glint at last 本文将复杂目标后向散射回波近似为目标上若干强散射中心回波的合成，结合几何光学法得到了某种飞机目标的确定性模型，并用该模型评定频率分集对角闪烁抑制的改善性能。
The ratma can calculate the electromagnetic scattering of multiple cylinders , and can be used in remote sensing . in chapter 2 simply derivation of the ratma is given by the addition theorem , and the general t matrix of single cylinder is deduced . the worked out examples show th e effectiveness of the ratma in the analysis of the scattering field of single cylinder or multiple cylinders 由于递推t矩阵法不仅可以计算多个柱体或不同形状柱体的散射，而且可计算遥感上三维物体的散射，在第二章中，利用加法定理，简要地推导了递推t矩阵法，并用解析法推出了单个圆柱体在各种情况下的t矩阵(此t矩阵对导体和介质圆柱体的散射场计算都适用) ，最后计算了单个导体圆柱和两个不同大小介质圆柱体的散射场。
This thesis in theory deals with electromagnetic wave scattering by multilayered confocal and non - confocal spheroidal particles illuminated by gaussian beams , in which the main contributions are as follows : 1 . in the case of multilayered confocal spheroidal particles , the scattered fields as well as the fields within each layer are obtained in terms of infinite series with spheroidal vector wave functions by using an appropriate expansion of the incident gaussian beam . by virtue of the boundary conditions , we write the set of equations for determining the unknown expansion coefficients and then solve it 本文从理论上研究了多层共焦和非共焦椭球粒子对高斯波束的散射，主要成果如下： 1 .我们研究了多层共焦椭球粒子对高斯波束的散射，把入射高斯光，散射场，各层椭球内的电场和磁场用适当的椭球矢量波函数展开，应用电磁场边界条件，写出确定各展开系数的方程组，求出散射场系数，进而求出散射场及散射截面。
Abstract : according to the continuative condition of the tangential fields on the slot aperture which is the inclined narrow - slot on the broadwall of a sectoral waveguide , the moment method is used to calculate the magnetic current coefficient and distribution . then the scattering field , the scattering parameter and the equivalent impedance are obtained . leting only the te11 dominant mode propagates in the waveguide , the scattering parameters and the normalized equivalent series impedance in the x - band are computed . the basis disigned the slot antenna and the slot array is offered 文摘:根据缝隙口面切向场的连续条件，采用解析数值法矩量法，对扇面波导宽壁上窄的斜缝进行了计算，解得了磁流系数及其分布，并得到散射场、等效散射参量及等效阻抗等重要参数.假定波导中仅有te11主模传输，在x波段计算了散射参量和归一化等效串联阻抗，给出计算结果，为缝隙天线和缝隙阵列设计提供了依据
In the end , the theory of fractal geometry is applied to the waves propagation and scattering in atmospheric turbulence , and the first and second order moments of the scattering fields are derived by considering the effects of the fractal atmospheric turbulence . the normalized back - scattering radar cross section of a perfectly conducting disk is calculated . the influence of fractal dimension of atmospheric turbulence on the radar cross section is analyzed 本文最后将分形理论引入到湍流大气中的波传播和散射领域，导出了分形大气湍流中光滑导体目标散射场的一阶矩和二阶矩，以光滑导体圆盘为例研究了湍流大气的分维对导体目标后向散射截面的影响。
From the model study of the fractal random rough surface , we acquire one dimensional ? two dimensional fractal random rough surface model with fractal theory ; 2 . the calculation of the scattering field of light ; the establishment of the scattering light ’ intensity model , and the number calculation of the intensity distribute ; 3 . the study on the laser radar cross section of one - dimensional fractal rough surface target ; and the number calculation of the scattering intensity of two - dimensional fractal the rough surface target ; 4 . through shadowing effect , we analysis light scattering characteristic of fractal rough surface 本论文利用分形理论得到一维?二维分形随机粗糙表面模型,研究光在一维?二维分形粗糙表面的光散射特性,主要从以下四个方面分析: 1 .自仿射分形随机粗糙表面模型探讨,采用分形理论得到一维?二维分形随机粗糙表面模型; 2 .分形粗糙表面散射光场的计算和粗糙表面散射光强角分布的模型建立和数值计算; 3 .一维分形粗糙表面目标的激光雷达后向散射截面lrcs研究和二维分形粗糙表面目标散射强度数值计算; 4 .引入遮蔽效应分析分形粗糙表面光散射特性。
