A Study on Lateral Wave for Edge Diffraction of Electromagnetic Wave by Dielectric Wedges

In this study, the edge diffraction of an electromagnetic plane wave by a two-dimensional dielectric wedge has been investigated by the extended PO (Physical Optics) approximation method [1]. The numerical results have then been compared with those of reference methods such as HRD (Hidden Rays of Diffraction) solution and FDTD (Finite-Difference Time-Domain) simulation. The comparison showed a good agreement between approximation methods and FDTD simulation in the outer region, while some significant differences can be observed inside the dielectric wedge as in Fig. 1(a). These differences remind us that an important contribution may be missed in our approximation solutions for the internal field. This problem is closely related to the boundary condition of the edge diffracted field, in which the diffracted field propagates in both outer and inner regions but with different wave numbers. Thus, the lateral wave is introduced to compensate for this difference between the two media.