Non-Uniform Gratings that Produce Preselected Anomalous Reflections

Abstract

We present a wire-impedance solution for an array of loaded wires above a ground plane that produces a preselected field when illuminated by a known plane wave. The preselected field consists of plane waves that are determined from a set of parameters, which salsify a periodicity condition. The solution determines both the wire impedances and the locations of the wires directly from the parameters of the preselected field. The preselected plane-wave parameters within one period determine how many different types of wires are needed. The number of degrees of freedom available for the grating design is increased by the number of different wires employed. We examine the ramifications of the solution when the preselected plane waves are tilted away from the generic directions observed in standard grating theory.