On the Electromagnetic Scattering From Deformed Spherical Dielectric Objects

In this article, an analytical investigation of electromagnetic scattering from deformed dielectric spheres using Debye potentials and the perturbation method is presented. To address a broad spectrum of scattering problems, azimuthal variation is included, which leads to scatterers with non-rotationally symmetric shapes depending on the θ and φ angles in spherical coordinates. The analysis of the scattered and transmitted fields is carried out explicitly up to the second order in the perturbation parameter, thereby achieving higher accuracy. The coefficients of the scattered and transmitted fields are expressed in terms of Clebsch-Gordan coefficients, facilitating the computation of results for new geometries through basic algebraic manipulations. Numerical results and comparisons are provided for several obstacle geometries, including irregular shapes and bodies of revolution, with different relative permittivities and permeabilities, in terms of backward, forward, and bi-static radar cross sections.