Electromagnetic Scattering from a Finite Cylinder with Complex Permittivity

Abstract

The scattering of electromagnetic radiation from a finite conducting cylinder with complex permittivity at an arbitrary orientation was analyzed using a first approximation to the iteration technique for the integro-differential equation first developed by Shifrin and later modified by Acquista. The classical Kerker solution for a simple infinite dielectric cylinder was extended to a more physically realistic solution accounting for a finite length cylinder with complex permittivity by a modified Drude conductivity approach. The diameter of the cylinder is on the order of one wavelength of the incident radiation. The lowest order approximation to the internal field solution for the iteration process is a function of the effective polarized electric field inside the cylinder and the polarization matrix of the scattering medium. The polarization matrix of the cylinder is determined from the electrostatic solution for a finite cylinder in a constant electric field, and is a function of the length to diameter ratio (aspect ratio) and the permittivity of the cylinder. The electrostatic solution for a finite cylinder does not permit a closed solution; therefore the cylinder is approximated by an inscribed ellipsoid which provides a converging analytic expression. Results are compared to published data. The complex frequency dependent permittivity of the cylinder material was modeled using a modified Drude conductivity approach. The effects of typical variations in the length, diameter, and bulk conductivity of the cylinder were analyzed for TE, TM and TEM polarizations.