A High-Frequency Solution for the Plane Wave Diffraction from a 90° Metallic Wedge with a Metamaterial Layer on the Top Surface

A uniform asymptotic solution is presented for evaluating the diffraction from a right-angled metallic wedge partially covered by a double negative metamaterial layer. A plane wave is assumed to impact the structure at skew incidence with respect to the edge. The problem is solved by means of an approach that is based on the physical optics approximation of surface currents radiating in the surrounding free space. The analytical procedure provides in a closed form expression of the diffraction matrix in the framework of the uniform geometrical theory of diffraction. The related diffracted field is able to counterbalance the discontinuities of the geometrical optics field, thus producing a continuous total field also in correspondence of the shadow boundaries.