TM scattering by conducting strips right on the planar interface of a three-layered medium
(EN)
Fikioris John, G
(EN)
Tsalamengas John, L
(EN)
Combining the Fourier transform with recently developed powerful singular integral equation methods, this paper investigates the scattering properties of a variety of two-dimensional, three-layered planar structures loaded by a strip or a couple of coplanar strips right on an interface. The primary excitation is (a) the lowest-order incident TM (to strip axis) surface wave mode or (b) an incident E-polarized plane wave. In the practical case where the entire space is magnetically homogeneous, the kernel of the integral equations is most conveniently decomposed into a singular closed-form term-represented by a linear combination of four Hankel functions-added to an exponentially convergent inverse Fourier integral. With the help of new analytical algorithms which completely and uniformly take into account the singular terms, an efficient, accurate, and stable numerical code is obtained. With its use the strip-induced current densities as well as any quantity of practical interest are determined. Plotted numerical results reveal that by a proper choice of certain geometrical parameters the structures may become very efficient radiators, which may be designed to exhibit either very wideband and high directivity or considerable frequency scanning.
(EN)
