One of the standard applications for demonstrating accuracy of electromagnetic (EM) codes in radar cross section (RCS) analysis is simulation of scattering from spheres made of perfect electric conductor (PEC). This application note demonstrates calculations of bistatic EM wave scattering from the electrically large PEC spheres 15 GHz using WIPL-D software.
Four models of PEC spheres were created and simulated using WIPL-D simulation software. The radius of the spheres was 50 wavelengths. The spheres of such a radius can be considered as electrically large objects (scatterers). The spheres are illuminated using EM plane wave. In order to decrease simulation time and number of unknowns, EM models of PEC spheres were simulated after applying three symmetry planes.
The results obtained after utilization of WIPL-D Pro, a 3D EM simulation software, are compared with results obtained by using Mie series. Lorentz-Mie series is the standard benchmark result used in case of accuracy demonstration and it is based on analytical solution for canonical geometries. On the other hand, exploited simulation software, WIPL-D Pro, is a full wave 3D EM Method-of-Moments (MoM) based solver which uses HOBFs (higher order basis functions). The software environment is used be used both, for modeling and simulation of the spheres. In addition, the matrix inversion computations are performed using WIPL-D GPU Solver, a WIPL-D add on tool. Comparing to some other volume-discretization based computational methods, with WIPL-D, volume discretization is not required. Also, the artificial boundaries like radiation boxes or perfectly matched layers are not required. All of these features contribute to the high accuracy and efficiency of the computations and make the method especially suitable for open-space problems, such is RCS calculation.