Numerical integration of physical optics for 2-dimensional scatterer using fresnel zone numbers with frequency-independent computation time

Many techniques to reduce the computational cost of the physical optics (PO) have been developed. In this paper, we introduce the technique for evaluation of radiation integrals in the PO, whose computational loads become independent of the frequency. Fresnel zone number is used for the criterion to localize and divide the radiation integrals. The proposed method was applied to the PO computation of the monostatic radar cross section (RCS) for the 2-dimensional conducting strip and rectangular cylinder. We found the good balance between the computational time and accuracy.