A uniform geometrical theory of diffraction for the scattering from quasi periodic finite planar arrays excited by a nearby antenna

Abstract

This paper presents a uniform geometrical theory of diffraction (UTD) for describing the electromagnetic (EM) scattering from finite, quasi periodic, planar arrays illuminated by incident spherical waves. It is applied here to analyze the scattering by a finite frequency selective surface (FSS), and by a finite reflectarray, respectively when they are excited by a nearby antenna. The UTD yields not only a relatively simple solution to these problems, but it also lends physical insights into the scattering mechanisms via Floquet modal rays arising from the interior points, and diffracted rays arising from the truncation boundaries, respectively, of such finite structures. Numerical examples are shown to validate the UTD analysis.