The Efficient High Frequency Methods on Electromagnetics Scattering

In this work, we give the recent progress on the fast methods for the high frequency scattered fields. The physical optics (PO) method is first considered with the numerical steepest descent path (NSDP) method on the complex plane. The NSDP method makes use of the high frequency critical points contributions. In each quadratic patch, the NSDP method could achieve frequency independent workload and error controllable accuracy for calculating the PO scattered fields. Then, with the quadratic discretization patch for realistic scatterer, the PO scattered fields could be calculated much faster than the traditional PO method with planar patch. Next, we extent the PO scattered fields with the muti-level technique to calculate the scattered fields for coated realistic scatterers. Meanwhile, on invoking the numerical contour deformation technique, we adopt the Fock currents and the incremental length diffraction coefficient (ILDC) technique to calculate the diffracted fields. The high frequency wave physics, including the creeping wave fields, are clearly captured with the numerical contour deformation method. The accuracies of the high frequency scattered fields are significantly improved compared with the results from the PO method.