A hybrid uniform geometrical theory of diffraction-moment method for efficient analysis of electromagnetic radiation/scattering from large finite planar arrays

A hybrid uniform geometrical theory of diffraction (UTD)-moment method (MOM ) approach is introduced to provide an efficient analysis of the electromag netic radiation/scattering from electrically large, finite, planar periodic arrays. This study is motivated by the fact that conventional numerical me thods become rapidly inefficient and even intractable for the analysis of e lectrically large arrays containing many antenna or frequency-selective sur face (FSS) elements. In the present hybrid UTD-MOM approach, the number of unknowns to be solved is drastically reduced as compared to that which is r equired in the conventional MOM approach. This substantial reduction in the MOM unknowns is essentially made possible by introducing relatively few, s pecial ray-type (or UTD) basis functions to efficiently describe the unknow n array currents. The utility of the present hybrid approach is demonstrate d here for the simple case of a large rectangular phased array of short and thin metallic dipoles in air, which are excited with a uniform amplitude a nd linear phase distribution. Some numerical results are presented to illus trate the efficiency and accuracy of this hybrid method.