阻抗球涂覆均匀等离子体电磁散射的解析解

Analytical solution to electromagnetic scattering by an anisotropic plasma-coated impedance sphere

均匀无源各向异性等离子体介质中的电磁场是第一、第二类各向异性等离子体球矢量波函数的线性叠加,在阻抗球表面满足阻抗边界条件、等离子体与自由空间表面满足电磁场切向连续的边界条件,可得出各向异性等离子体涂覆阻抗球在平面波入射情况下,均匀等离子体介质中电磁场用各向异性等离子体球矢量波函数表示的系数满足的矩阵方程,进而得出散射场由球矢量波函数展开的展开系数和雷达散射截面。数值计算的结果表明:当阻抗球的半径趋于0时,其结果和均匀各向异性等离子体球对平面波的电磁散射结果相同。最后还给出了一些数值计算的结果。

In source-free plasma anisotropic medium, the electromagnetic fields can be expressed as integral of the first and the second spherical vector wave functions. By applying the boundary conditions in the interface of impedance sphere and the continue boundary condition between plasma anisotropic medium and free space, the matrices equation of the expansion coefficients of electromagnetic fields can be derived in terms of spherical vector wave functions in plasma anisotropic medium, and then the scattering coefficients of scattering fields in terms of spherical vector wave functions in isotropic medium and the Radar Cross Section （RCS） of an anisotropic plasma-coated impedance sphere by a plane wave can be obtained Numerical results show that when the radius of impedance sphere approach zero （for example, 0. 001X, where X is the wavelength of incident wave）, the present numerical result is in a good agreement with that of the homogeneous plasma anisotropic sphere. Also, some new numerical results of a plane wave scattering by an anisotropic plasma- coated sphere are presented in this paper