A fast and simple method to analyze finite ground plane effects in large grounded slot arrays

In principle, once the current distribution is known, the scattered field can be easily evaluated. However, when the ground plane is in the induction field of the sources, the currents induced on it vary so rapidly that the computation of the radiation integral becomes very time consuming. The idea at the basis of this work is therefore to reconstruct the field radiated by the finite ground plane as the difference between the infinite plane and the external frame contributions. The discrete Fourier transform is used to further speed up the computation of this latter contribution. The resulting procedure, though conceptually very simple, offers a significant saving in computational time with respect to a traditional physical optics (PO) approach, while retaining the same accuracy