ON THE ELECTROMAGNETIC SCATTERING FROM INFINITE RECTANGULAR GRIDS WITH FINITE CONDUCTIVITY

The development of a new numerical technique for the analysis of electromagnetic scattering from a rectangular wire (or strip) mesh is reported. According to this technique, the conjugate gradient method (CGM) and the fast Fourier transform (FFT) are used to solve for the aperture fields and the induced current densities. The method is efficient because it makes use of the fast Fourier transform, it converts a set of integrodifferential equations into a set of algebraic equations, and it does not require inversion of any matrices. Unlike the moment method, the spectral iteration approach (SIT), and the averaged boundary conditions method, this technique can be used for arbitrary size and spacing between adjacent strips. The equivalent radius principle is used to determine the reflection coefficient from a wire mesh. Results, examples, and comparisons of this method with other methods support the validity of the algorithm.