ELECTROMAGNETIC WAVE SCATTERING FROM STRIP IN THE PRESENCE OF CHIRAL MEDIUM USING KOBAYASHI POTENTIAL METHOD

Abstract

In this study, scattering of electromagnetic plane wave from an impedance strip located at an infinitely extended planar interface has been presented. One half space of the geometry is occupied by free space medium whereas other half space is that of the chiral medium. Assuming that chiral medium is lossless, reciprocal, homogeneous and thickness of the strip is negligibly small, Kobayashi potential method has been used as method for analysis. In order to develop good understanding of the Kobayashi potential method when applied for study of scattering in the presence of chiral medium, simple situations are first considered. As analysis of scattering in an unbounded medium is simpler than that in the presence of interface and perfect electric conducting surface is considered a special case of impedance surface. So, a perfect electric conducting strip placed in an unbounded chiral medium is treated first followed by an impedance strip in unbounded chiral medium. Finally, scattering from perfect electric conducting strip and impedance strip at the planar interface of free space and chiral mediums is investigated. In the problem formulation generic form of scattered fields which satisfy two dimensional Helmholtz ‟ s equation with unknown weighting functions is considered. To satisfy a set of boundary and edge conditions properties of Weber-Schafheitlin integral are applied. In this step, unknown weighting functions are also written in terms of unknown expansion coefficients which are determined by applying the remaining boundary conditions and orthogonal properties of the Jacobi polynomials. Far zone scattered fields are determined by applying the Saddle point method of integration. For different parameters of interests, the monostatic and bistatic scattering widths have been analyzed numerically. The convergence of solution corresponding to the number of expansion coefficients is also examined numerically.