Radially inhomogeneous spherical structures; analysis of EM scattering using Taylor's series method and their potential applications

Spherical structures have always been among the most frequently studied topics by researchers in engineering electromagnetics. In this paper, electromagnetic (EM) scattering from radially inhomogeneous spherical structures is investigated in the most general cases. Unlike previous investigations, these structures are studied based on an exact frequency domain method without any approximations. Two main categories of applicable inhomogeneous spherical structures exist: inhomogeneous spheres and spherical arbitrary cores, coated with a radially inhomogeneous layer. One of the biggest advantages of this research investigation is the generality and inclusiveness in analyzing all of the aforementioned circumstances. The validity of the proposed method is verified for some special types of inhomogeneous structures through comprehensive examples. In the last section, the proposed method is used for designing of the optimized new class of lens based on the physical concept of gradient refractive index material, and radar cross section reduction based on gradual wave absorption. The proposed approach can be used for other interesting applications such as designing radar absorbers, cloaks and radomes for spherical structures in future researches. (C) 2017 Elsevier GmbH. All rights reserved.