Reducing computational workload of electromagnetic scattered fields from electrically large quadratic surface at high frequency

We use the numerical steepest descent path (NSDP) method to calculate the highly oscillatory physical optics (PO) scattered fields on electrically large quadratic surfaces. The resultant phase behaviors of PO integrands are elliptic and hyperbolic on parabolic and saddle quadratic patches, respectively. The proposed method relies on deforming the integration path of the PO integral into the NSDPs on the complex plane. Numerical results of the PO scattered fields on these smooth conducting quadratic surfaces illustrate that the proposed NSDP method gains high accuracy while the workload is frequency independent.