Truncation Diffraction Phenomena of Floquet Waves Radiated From Semi-Infinite Phased Array Antenna in a General Focus Problem

This paper presents uniform formulations of radiation mechanisms, analogous to the ray decompositions of diffraction theory, from a semi-infinite and periodic array of antennas. The antenna array is excited to radiate the electromagnetic (EM) fields focused at a relatively arbitrarily selected location. The ray decomposition results from a closed-form formulation by asymptotically evaluating the radiation integral of Floquet modes that are obtained by applying the Poisson sum formula to the summation of elemental radiations. The analysis is relatively general and will reduce to the case of a conventional phased array antenna that is excited to radiate directive beams focused in the far zone, and exhibits consistent phenomena. Theoretical investigations as well as numerical examinations are presented to demonstrate the radiation mechanisms.