EM PLANE-WAVE DIFFRACTION BY A PLANAR JUNCTION OF 2 THIN MATERIAL HALF-PLANES - OBLIQUE-INCIDENCE

A uniform geometrical theory of diffraction (UTD) solution is develope d for analyzing the phenomenon of high-frequency diffraction of an obl iquely incident plane wave by a two-part thin, planar transparent mate rial slab. The solution is obtained by appropriately combining two sol utions for the two related configurations involving perfectly conducti ng electric and magnetic ground plane bisections of the original slab. The analysis is based on the Wiener-Hopf technique, and each of the g rounded material half-planes is assumed to be electrically thin so tha t it can be modeled by a generalized impedance boundary condition of 0 (t), where t is the corresponding slab thickness. It is shown that to solve the boundary value problem completely, an additional condition r elated to the field behavior at the junction of the two material half- planes needs to be imposed besides the boundary and radiation conditio ns as well as the usual edge condition. This junction condition is det ermined by matching an approximate quasi-static solution, which is dev eloped in the proximity of the discontinuity, with the corresponding e xternal Wiener-Hopf solution in the common region of overlap. The solu tion thus obtained automatically satisfies reciprocity. It is shown th at the new UTD solution obtained here reduces to known results and the numerical results based on it agree very well with a corresponding in dependent moment method solution.