Abstract

The problem of electromagnetic scattering by a circular-grooved corrugated ground plane is treated in a cylindrical coordinate system (ρ, ϕ, z), where the solution assumes a 2π periodicity in direction. Thus, the solution can be expanded in a Fourier series in ϕ and can be decomposed into two orthogonal polarizations according to vector field theory. They are the fast polarization, H_ϕ = 0 and the slow polarization, E_ϕ = 0. Furthermore, these two polarizations can be uniquely determined by E_ϕ and H_ϕ, respectively, each represented in the form of an integral involving Bessel functions. For the nth mode in the Fourier series expansion, they are where r_n(ξ) is the unknown function amenable to electromagnetic boundary conditions. It is found that r_n(ξ) can be constructed by another series of Bessel functions through the techniques of Hankel transforms. The coefficients of the series can be determined by enforcing the continuity of tangential fields in the groove aperture. Simulation results will be presented to show that the boundary-value techniques are efficient and computationally stable.

© 1992 Optical Society of America