Oblique Diffraction of Arbitrarily Polarized Waves by an Array of Coplanar Slots Loaded by Dielectric Semi-Cylinders

We study oblique diffraction of arbitrarily polarized plane-waves by a finite array of slots of infinite length on a common ground plane, backed by an array of dielectric semi-cylinders. The formulation is based on a combined eigenfunctions expansion and integral equation approach. For the diffracted field, series expansions in cylindrical wave functions are used to which several singular integral terms are superimposed that fully account for the presence of each of the slots. The relevant system of singular integral equations is discretized by an exponentially convergent Nyström method. Noticeably, all matrix elements take simple closed-form expressions. Numerical examples and case studies illustrate the convergence of the algorithm and bring to light the influence of the dielectric loads on the characteristics of the structure.