Scattering from a 90° Metallic Wedge with One Face Coated by a Double Negative Metamaterial Layer

This manuscript refers to the electromagnetic scattering problem involving plane waves at skew incidence with respect to the edge of a right-angled metallic wedge having one face coated by a double negative metamaterial sheet. Its presence in the propagation scenario is properly accounted at high frequencies by considering the geometrical optics response of the structure and the diffraction contribution arising from the edge of the wedge. In particular, the reflection coefficients related to the coated surface are determined for both the polarizations by using the equivalent transmission line circuit, whereas the diffraction coefficients are obtained by applying the uniform asymptotic physical optics approach. This last is based on electric and magnetic equivalent surface currents under the physical optics approximation and permits to evaluate the diffraction contribution in the context of the uniform geometrical theory of diffraction. The resulting approximate solution is characterized by the same simplicity of use of the heuristic solutions and provides reliable field values as confirmed by the numerical tests carried out by a full-wave commercial software.