In this paper, an improved complex image method to derive closed form periodic Green’s function for problem of scattering from perfectly conducting periodic surfaces is considered. The complex image technique represents a close-form periodic Green’s function consisting of a finite series of real sources and two finite series of complex sources with complex locations and amplitudes. Then the integral equation with the complex images periodic Green’s function in the kernel is solved by the method of moments. Results and computational times obtained by this improved complex image method and the previous one are compared with those obtained by the spectral Kummer-Poisson’s method. Results show that the improved complex image method is more accurately than the previous one.
