A Frequency-Independent Method for Computing the Physical Optics-Based Electromagnetic Fields Scattered From a Hyperbolic Surface

In this communication, we propose a frequency-independent approach, the numerical steepest descent path (NSDP) method, for computing the physical optics scattered electromagnetic field on the quadratic hyperbolic surface. Due to the highly oscillatory nature of the physical optics integral, the proposed method relies on deforming the integration path of the integral into the NSDP on the complex plane. Numerical results for the PO-based EM fields from the hyperbolic surface illustrate that the proposed NSDP method is frequency independent in computational cost and error controllable in accuracy.