Hidden rays on the shadow boundaries of penetrable wedges

Reflection and refraction of ordinary rays occur only on lit boundary without considering the field singularity at edges. In electromagnetic diffraction by a wedge, a systematic way on tracing hidden rays reflected and refracted on its shadow boundary was implemented in the complementary regions, which were well defined in the formulation of dual integral equations. And then, the angular period of its extended physical optics (PO) diffraction coefficients are adjusted to satisfy the edge condition at wedge tip. This procedure is applied to E-polarized diffraction by a composite wedge composed of a perfect conductor and a lossy dielectric. The diffraction coefficients and field patterns are plotted here, and compared to the conventional PO solution.