The Fast Solver for Calculating the High Frequency Scattered Fields from the NURBS Scatterers

In this paper, the physical optics (PO) scattered field aroused by the perfect conducting quadratic surface is studied comprehensively. Via using the numerical steepest descent path method (NSDP), the high oscillatory physical optics integral is calculated efficiently. Compared with the traditional approximate asymptotic expansion method, the NSDP method improve the accuracy for evaluating the PO integral. The computation effort of the NSDP method is also frequency independent. The hybrid method by combining with the GRECO method is used for calculating the PO scattered field exciting from complex NURBS surface targets. Finally, we using the Fourier quadrature method calculate the high diffraction fields aroused by the the perfect conducting circular cylinder.