High frequency scattering by a smooth coated convex cylinder simulated with higher order impedance boundary conditions

The authors present a rigorous uniform theory of diffraction (UTD) solution of the diffraction by a coated convex cylinder simulated with generalized impedance boundary conditions (GIBC). In addition, a uniform asymptotic solution is obtained which remains valid when the observation point is in the close vicinity of the cylinder. An important aspect of this work is the use of second-order GIBCs which are characterized by the inclusion of second-order field derivatives in their definition. Because of this, they are less local, leading to an improved simulation (with respect to the standard impedance boundary conditions) of the coating. The improved accuracy of the GIBC simulation is demonstrated, and it is shown how the presented UTD solution can be extended to treat multilayered coated cylinders.<>