Scattering from an infinite conducting cylinder covered with a finite two-layer dielectric coating (modal approach)

The electromagnetic scattering problem of a conducting infinite circular cylinder partially shielded with a finite two-layer dielectric coating has been analyzed. Cylindrical eigenfunctions with unknown modal coefficients are used to expand the interior EM fields in terms of Fourier-Bessel series. Enforcing field boundary conditions at the dielectric-dielectric interface leads to a single set of modal coefficients for field expansions inside the inner and the outer dielectric layers. Replacing the dielectric coating with the induced polarization sources and utilizing pertinent Green's functions, the dielectric-scattered fields are then formulated in terms of the modal coefficients. Imposing field equivalence conditions yields sets of linear algebraic equations for numerical computation of the unknown modal coefficients and subsequently other parameters of interest. Computed backscattered fields based on the modal technique developed are compared to experimental and numerical data obtained for the 2-D problem of a dielectric coated conducting cylinder.