Plane Wave Diffraction by a Non-Planar DPS-DNG Junction in the Case of Normal Incidence

This paper solves the diffraction problem associated to a plane wave impacting a non-planar junction of two lossy planar slabs with different electric and magnetic characteristics. One slab consists of a standard double positive material whereas an unusual double negative metamaterial is used for the other slab. A uniform asymptotic solution is proposed in the framework of the uniform theory of diffraction when the incidence direction is orthogonal to the edge of the junction. Such a solution is based on the physical optics approximation of the electric and magnetic equivalent surface currents assumed as radiating sources in the surrounding space and used in the far-field radiation integral. This last denotes the starting point of an analytical procedure that provides closed form expressions containing the transition function of the uniform theory of diffraction and the geometrical optics contribution of the junction. The resulting diffracted field is able to compensate the jumps of the geometrical optics field at the shadow boundaries.