Approximate boundary conditions for thin chiral layers with curvilinear surfaces

One- and two-sided impedance approximate boundary conditions are obtained for a thin chiral layer with a coordinate surface described in generalized orthogonal curvilinear coordinates. The problem of diffraction of a plane electromagnetic wave by an infinite circular chiral-metallic cylinder is considered as an example illustrating the application of such conditions for calculation of reflecting structures with chiral layers. The main component of the field diffracted by the reflecting structure under study is calculated with the use of the approximate boundary conditions and by means of a rigorous approach, and the results obtained with the help of the two methods are compared.