Electromagnetic Scattering from Anisotropic Inhomogeneous Impedance Cylinder of Arbitrary Shape with Generalized Impedance Boundary Condition

In this paper, the electromagnetic scattering from inhomogeneous anisotropic impedance cylinder of arbitrary shape, whose surface satisfies most general impedance boundary, is investigated by Method of Moments (MoM). Cylinder is illuminated by monochromatic plane wave polarized in the cylinder axis (z-axis). The scattered field is calculated using the electric field integral equation of Stratton-Chu. current continuity equation and two-dimensional Green's function. In consideration of the difficulty in solving the vector integral equation, transformation from cylindrical coordinates to Cartesian coordinates is adopted to simplify the electric field integral equation using impedance boundary condition. For simplicity and high efficiency, pulse basis expansion functions are chosen for MoM. It is noteworthy that not only the induced electric current, but also the induced magnetic current and electric charge make contribution to the scattered field, so the derivative of pulse function will appear in the equation. Differential is replaced by difference to cope with the derivative of pulse function as an approximation. When the integral terms appear in the expression of impedance matrix elements, QDAGS function in the IMSL Libraries is used to ensure the accuracy of the calculation. Once the radius of the cylinder is equal to a constant value, the proposed method in this paper is still valid. Obtained scattering width results are compared with those obtained by analytical method or physical optics (PO) method, and good agreements are observed.