Extended asymptotic corrugation boundary conditions

The asymptotic corrugation boundary conditions (ACBCs) are extended to analyze scattering from corrugated surfaces having non-uniform cross-section. Enforcing the ACBCs yields the reflection and transmission coefficients as well as the field distribution inside corrugations. Results obtained using the present theory exhibit an excellent agreement with full-wave simulations. The possibility of synthesizing artificial anisotropic dielectrics using corrugated surfaces is also demonstrated.