Study On Electromagnetic Scattering Of Coated Sphere By Complicated Material

Due to the significance of theoretical research and wide application prospect in the fields of grain size analysis, electromagnetic remote-sensing, biomedicine and electromagnetic invisibility and so on, the interactions between electromagnetic(light) wave and complicated sphere is treated as one of the international heated research topic. Until now, researches on internal and near fields of uniaxial coated sphere and scattering properties of double negative coated sphere by electromagnetic(light) wave has rarely been published, which is worth to be further studied. The main work and results in the thesis are as follows:1. Based on the orthogonality and complete property of spherical vector wave functions and Fourier transformation, internal electromagnetic fields of uniaxial anisotropic sphere by Gaussian beam are derived, with the help of the boundary conditions in electromagnetics, scattering coefficients can be achieved, then the computed formulas of far-field RCS and internal, near fields are obtained. The effects of the beam width, off-axis position, permittivity and permeability tensor elements on far-fields RCS and internal-near fields are numerically discussed.2. Considering the construction of the electromagnetic fields of the shell, the scattering coefficients of uniaxial anisotropic coated sphere is derived, then the computed formulas of far-field RCS and internal, near fields are further obtained. The effects of the beam width, off-axis position, permittivity and permeability tensor elements on far-fields RCS and internal-near fields are numerically calculated and discussed.3. As a consequence of that the double negative material is still complying with Maxwell functions and Snell’s laws, grounded on Wu’s recursive algorithms of electromagnetic scattering on multi-layered sphere by a plane wave, scattering properties of double negative coated sphere are numerically analyzed, especially effects of refractive index of the core and the ratio for the thickness of the core with the shell are discussed.