Electromagnetic scattering from a chiral cylinder of arbitrary cross section

• Published in: IEEE transactions on antennas and propagation Vol. 44; no. 7; pp. 1041 - 1048
• Main Authors: Al-Kanhal, M.A., Arvas, E.
• Format: Journal Article
• Language: English
• Published: IEEE 01.07.1996
• Subjects: Dielectrics; Eigenvalues and eigenfunctions; Electromagnetic fields; Electromagnetic scattering; Integral equations; Moment methods; Optical polarization; Optical scattering; Optical surface waves; Tellurium
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/8.504313

A simple moment solution is presented to the problem of electromagnetic scattering from a homogeneous chiral cylinder of arbitrary cross-section. The cylinder is assumed to be illuminated by either a TE or a TM wave. The surface equivalence principle is used to replace the cylinder by equivalent and magnetic-surface currents. These currents radiating in unbounded external medium produce the correct scattered field outside. When radiating in an unbounded chiral medium, they produce the correct total internal field. By enforcing the continuity of the tangential components of the total electric field on the surface of the cylinder, a set of coupled integral equations is obtained for the equivalent surface currents. Unlike a regular dielectric, the chiral scatterer produces both copolarized and cross-polarized scattered fields. Hence, both the electric and magnetic current each have a longitudinal and a circumferential component. These four components of the currents are obtained by using the method of moments (MoM) to solve the coupled set of integral equations. Pulses are used as expansion functions and point matching is used. The Green's dyads are used to develop explicit expressions for the electric field produced by two-dimensional surface currents radiating in an unbounded chiral medium. Some of the advantages and limitations of the method are discussed. The computed results include the internal field and the bistatic and monostatic echo widths. The results for a circular cylinder are in very good agreement with the exact eigenfunction solution.