A systematic study of the impedance boundary condition (EM scattering)

A numerical study of the impedance boundary condition has been carried out with the objective of evaluating its applicability to several representative, planar, two-dimensional (2D) inhomogeneous scatterers. Three basic classes of 2D structures are considered: an infinite-depth trough structure, a finite-depth trough structure, and a linearly tapered trough. These problems were solved using the method of moments in two ways. In the first, a surface integral equation (SIE) approach was used as a baseline and was considered to be a numerically rigorous solution. In the second, the 2D structure was reduced to a 1D structure having an equivalent surface impedance. Results obtained for the three structures are presented.<>