共查询到15条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
基于矩量法、互易性定理及镜像理论,提出了一种新的混合方法用于研究水平分界面上方二维介质目标对垂直入射高斯波束的差值散射场.应用镜像理论,介质水平分界面可被原始目标相对于该分界面的镜像目标所替代,从而给出散射问题的等效模型.在等效模型中,应用矩量法求解了原始目标及镜像目标对高斯波束的散射场,同时结合互易性定理得到了原目标与其镜像目标之间的耦合散射场.数值计算结果与相关文献方法及MoM所得结果进行了比较,验证了该混合方法的有效性.
关键词:
互易性定理
电磁散射
高斯波束
二维目标 相似文献
5.
基于广义洛仑兹-米氏理论(GLMT),研究了高斯波束对离心球的纵向辐射俘获力.用积分区域近似法计算波束系数,散射场的展开系数由矢量球面波函数的加法定理并求解边界条件得到.给出了高斯波束对在轴离心球辐射俘获力的计算公式并进行了数值模拟.将离心球退化为同心双层球,对离心球辐射俘获力的公式进行了验证.讨论了离心距对纵向俘获力的影响,也讨论r束腰半径、介质折射率和波长对纵向辐射俘获力的影响. 相似文献
6.
根据广义米氏理论,将入射的高斯波束按矢量球谐函数展开,获得了波束因子(展开系数)gmn,TM和gmn,TE的一般表达式。应用gmn的局域近结果和散射系数anm和bnm的迭代公式与算法,研究了多层有耗介质球的光散射。讨论了波束宽度与球形粒子的尺寸和位置对散射系数和散射强度角分布的影响。 相似文献
7.
提出了一种将任意入射波束因子用矢量波函数展开的方法,根据波束在球坐标系中的展开形式,以及球谐矢量函数与非球坐标系的波矢量函数之间的关系,推导出任意入射波束在相应坐标系中的波束因子的理论表述形式.以椭球坐标系为例,介绍了将离轴的入射波束,用椭球矢量波函数展开的波束因子求解方法,此方法还可应用于柱坐标、椭柱坐标系中波束因子的求解,为研究粒子对任意入射波束的散射打下了基础.
关键词:
波束因子
广义米理论
光散射 相似文献
8.
非球形大气粒子对任意波束的电磁散射特性 总被引:3,自引:6,他引:3
研究大气中变形球状的气象粒子对电磁波以及激光的散射特性,采用广义米氏(Mie)理论,精确地求解在任意波束中大气粒子的散射强度,数值计算激光束腰位置对散射强度分布的影响,分析彩虹强度和散射角与变形球状粒子偏心率的关系,研究随着长短轴比例增加,彩虹强度峰值的偏移。计算结果表明雨滴在下降过程中,它在各个方向的光散射强度逐步减弱,即随着雨滴偏心率的增大,散射强度减少,彩虹角变大。对于激光入射,当粒子距离波束中心位置越远,粒子的散射就越弱,并且随尺寸参量增加,后向散射振荡的频率要大于前向散射,当束腰位置矢径的大小增加时,后向散射和前向散射强度均变小。 相似文献
9.
10.
11.
Electromagnetic scattering from two parallel 2D targets arbitrarily located in a Gaussian beam 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper based on the equivalence principle and the reciprocity theorem, the
scattered field up to second-order by two parallel 2D targets arbitrarily located in
a Gaussian beam is considered. The first-order solution can easily be obtained by
calculating the scattered field from isolated targets when illuminated by a Gaussian
beam. However, because of the difficulty in formulating the couple scattering field,
it is almost impossible to find an analytical solution for the second-order
scattered field if the shapes of 2D targets are not canonical geometries. In order
to overcome this problem, in this paper, the second-order solution is derived by
using the technique based on the reciprocity theorem and the equivalence principle.
Meanwhile, the relation between the secondary scattered field from target #1 and
target {\#}2 is obtained. Specifically, the bi- and mono-static scattering of
Gaussian beam by two parallel adjacent inhomogeneous plasma-coated conducting
circular cylinders is calculated and the dependence of attenuation of the scattering
width on the thickness of the coated layer, electron number density, collision
frequency and radar frequency is discussed in detail. 相似文献
12.
Makoto Ohki Haruo Sakurai Jun Horikoshi Syogo Kozaki 《International Journal of Infrared and Millimeter Waves》1996,17(10):1707-1718
Rigorous expression of the electromagnetic beam wave scattering by N circular cylindrical models is described. To check this method, comparison between exact solution and this model composed of N=24 circular cylinders is presented for a single circular conducting cylinder. Numerical results of conducting square cylinder has been also checked with well-known result (B.E.M). 相似文献
13.
基于等效原理和互易性定理,研究了N个相互平行二维柱体对平面波/高斯波束的电磁散射特性,给出了求解N阶散射场公式.一阶散射可通过求解单个柱体的散射场得到,但对于高阶散射场而言,由于耦合散射的复杂性,很难给出精确的解析解.为了解决这一问题,借助等效原理和互易性定理给出了求解N阶散射场的面积分公式.只要给出柱体的i-1阶散射场及相关目标表面上的等效电流和(或)等效磁流,就可应用此公式求解i阶散射场.应用该近似方法计算了相互平行非均匀等离子体涂层导体圆柱的单/双站散射宽度,讨论了束腰半径、等离子体涂层厚度、电子密度、碰撞频率及雷达频率等对散射结果的影响. 相似文献
14.
YunFei Lui ShengCai Shi ShengLin Yu 《International Journal of Infrared and Millimeter Waves》2002,23(12):1727-1742
In this paper, the scattering formulae of a Gaussian electromagnetic beam by a cylindrical wire grid are derived. For the summation of Hankel functions, we adopt an integral form of lattice sums, which is developed by Yasumoto and Yoshitomi, to speed up convergence. The reflected and transmitted characteristics of a Gaussian beam by an actual wire grid are thoroughly investigated. Detailed simulation results are presented. 相似文献
15.
Based on spherical vector wave functions and their coordinate rotation theory,the field of a Gaussian beam in terms of the spherical vector wave functions in an arbitrary unparallel Cartesian coordinate system is expanded.The beam shape coefficient and its convergence property are discussed in detail.Scattering of an arbitrary direction Gaussian beam by multiple homogeneous isotropic spheres is investigated.The effects of beam waist width,sphere separation distance,sphere number,beam centre positioning,and incident angle for a Gaussian beam with two polarization modes incident on various shaped sphere clusters are numerically studied.Moreover,the scattering characteristics of two kinds of shaped red blood cells illuminated by an arbitrary direction incident Gaussian beam with two polarization modes are investigated.Our results are expected to provide useful insights into particle sizing and the measurement of the scattering characteristics of blood corpuscle particles with laser diagnostic techniques. 相似文献