均匀介质圆柱对平面波的散射(Mie级数)..docVIP

均匀介质圆柱对平面波的散射 1. TMz极化 假设TMz极化均匀平面波垂直入射半径为a的无限长均匀介质圆柱，相对介电常数为εr，相对磁导率为μr，波的传播方向为+x，入射电场和入射磁场用柱面波展开，分别表示为 (1) (2) 散射场朝外传播，因此，散射电场和磁场用柱第二类Hankel函数展开，分别表示如下 (3) (4) 透射场则由柱面基本波函数的线性组合表示，由于透射场在介质内部均为有限大，因此 (5) (6) 根据介质表面的边界条件，切向电场和切向磁场连续，可以得到 (7) (8) 求解方程组，从而得到展开项的系数为 (9) (1 0) 令，将系数带入展开式，得到散射电场和磁场的表达式为 (11) (12) 对于远区散射场，kρ → ∞，，则相应的电场和磁场为 (13) (14) c********************************************************************** c Compute TMz Scattering from homogenerous lossless dielectric Circular c Cylinder by Mie Series c c a INPUT, real(8) c On entry, a specifies the radius of the circular cylinder c epsR INPUT, real(8) c On entry, epsR specifies the relative permittivity of c the homogenerous dielectric circular cylinder c MuR INPUT, real(8) c On entry, muR specifies the relative permeability of c the homogenerous dielectric circular cylinder c f INPUT, real(8) c On entry, f specifies the incident frequency c r INPUT, real(8) c On entry, r specifies the distance between the observation c point and the origin of coordinates c ph INPUT, real(8) c On entry, ph specifies the observation angle c Ez OUTPUT, complex(8) c On exit, Ez specifies the z component of the electric c scattering field c Hpho OUTPUT, complex(8) c On exit, Hpho specifies the pho component of the magnetic c scattering field c Hphi OUTPUT, complex(8) c On exit, Hphi specifies the phi component of the magnetic c scattering field c c Programmed by Panda Brewmaster c********************************************************************** subroutine dSca_TM_DIE_Cir_Cyl_Mie(a, epsR, muR, f, r, ph, Ez, Hpho, Hphi) c********************************************************************** implicit none c - Input Parameters real(8) a, epsR, muR, f, r, ph complex(8) Ez, Hpho, Hphi c - Constant Numbers real(8), parameter :: pi = 3.141592653589793 real(8), parameter :: eps0 = 8.854187817d-12 real(8)