Diffraction by a Structure Composed of Metallic and Dielectric 90 degrees Blocks

This letter deals with the plane wave diffraction by a composite structure consisting of metallic and lossless dielectric 90 degrees blocks, which are adjacent and share the edge. Such a problem is first tackled in the frequency domain, and the related diffraction coefficients are determined by exploiting the uniform asymptotic physical optics approach. The inverse Laplace transform is applied to obtain the time-domain counterparts, which can be used to compute the transient diffracted field due to an arbitrary function plane wave.