The Two-Dimensional Numerical Steepest Descent Path Method for Calculating the Physical Optics Scattered Fields From Different Quadratic Patches

In this article, the Two-Dimensional numerical steepest descent path (TD-NSDP) method is proposed to calculate the physical optics (PO) scattered fields from the quadratic patches. Compared with the NSDP method, the TD-NSDP method avoids adopting the complementary error function, and hence, the TD-NSDP method could significantly improve the accuracy of the PO scattered fields by around four to five digits. Moreover, the computational workload is also frequency independent. To demonstrate the efficiencies of the TD-NSDP method, numerical examples for both quadratic convex and concave surface patches are conducted. Finally, the radar cross section (RCS) simulation from the realistic and complex scatterer is conducted to verify the practicability of this method in electromagnetic (EM) scattering application.