MICROWAVE SCATTERING FROM METAMATERIAL BASED SPHERES IN THE PRESENCE OF A CONDUCTING PLANE: NORMAL INCIDENCE

Abstract

The microwave scattering characteristics of a metamaterial (MTM) sphere and an MTM coated conducting sphere is compared to that of its DPS (Real(e) > 0, Real(μ) > 0) counterpart in the presence of an infinite conducting plane using the multipole expansion method and is presented in this article. The DPS medium may be an artificial dielectric or natural dielectric. The differential scattering cross sections and the differential backscattering cross sections of the different types of spheres are presented for a circularly polarized (left or right) beam incident normally on the sphere. The results presented may be useful for maritime applications. In this paper the theoretical scattering characteristics of microwaves from a sphere made of MTMs and a conducting sphere coated with MTMs, in the presence of an infinite conducting plane are presented. The motivation for this research arose from the works of Johnson (1) in which similar analysis is presented but with a dielectric sphere. The multipole expansion method was made use of in that effort to present the scattering characteristics of a dielectric sphere in the presence of a conducting plane. Methods used previously (references therein Johnson (1)) were approximation methods. The multipole expansion method is not an approximation, but rather provides a numerically exact solution to Maxwell's equations. The underlying principle used in this analysis is based on image theory, which has been extensively studied and researched (references therein Johnson (1)). The results presented in this paper may be useful for maritime applications (2, 3) and were obtained from computations performed by a program written in MATLAB.