Edge fringe approach for the full-wave solution of large finite arrays

The electromagnetic modeling of large finite arrays has been the object of a number of investigations. A method of moment (MoM) formulation is suggested, for predicting the distributions of the radiating currents (including those belonging to the edge elements of the array) but retaining a number of unknowns which is comparable with those occurring in the infinite array approach. This formulation is based on an integral equation in which the unknown function is the difference between the exact current distribution on the truncated array and the current distribution pertinent to an infinite array. This unknown function can be associated to the field diffracted at the edge of the array by the Floquet modes of the infinite array. Following this physical interpretation the unknown of the integral equation are efficiently represented by a few entire domain basis functions which are properly shaped.