Scattering by Large Size Cylinders Analysis via the Extended Method of Auxiliary Sources in Conjunction with the Partial Coupling

The scattering of a transverse magnetic plane wave by a large, infinite and dielectric cylinder is analyzed by an efficient approximation based on the extended method of auxiliary sources (EMAS) in conjunction with partial coupling. To reduce the computational cost of such scattering problem, we approximate the two auxiliary sources bases spread around the boundary by two bases of strips which are themselves formed by a reduced number of auxiliary sources. The overall number of auxiliary sources is reduced by almost 50%. The two sets of strips are distributed on both sides of the boundary so that they are staggered. The partial coupling consists of taking into account only the electromagnetic effect of neighboring strips when a point collocation is considered. Imposing the standard impedance boundary conditions (SIBC) leads to a linear system, from which one can easily deduce the magnitude and the phase of the unknown currents. Therefore, the scattered and inner fields are determined as a function of these currents. To validate the accuracy of the suggested approximation, numerical results was carried out on two large dielectric cylinders. For a transverse magnetic (TM) incidence, their backscattering radar cross-sections were calculated and compared to those found in the literature.