Diffraction by a Planar Junction between DPS and DNG Material Sheets: the UAPO Solution for Plane Waves at Skew Incidence

The plane wave diffraction by a planar junction between two lossy planar sheets is studied in this paper when the incidence direction is oblique to the rectilinear discontinuity of the structure. One slab consists of a standard double positive material, whereas an unusual double negative metamaterial is considered for the other slab. The uniform asymptotic physical optics approach is applied to find an efficient and user-friendly solution in the context of the uniform geometrical theory of diffraction. Such an approach is based on electric and magnetic equivalent sources radiating in the free space, and exploits an analytical process to obtain a closed form expression of the diffraction coefficients under the highfrequency assumption. A useful matrix representation is presented.