Generalized ray interpretation of floquet modes for two-dimensional, infinite phased array antennas

The Floquet modes of a two-dimensional (2-D), infinite periodic array of antennas with its radiation focusing at an arbitrary location, are investigated. The work is motivated by the incompleteness of array theory to treat this type of problem. In particular, a ray-based mechanism previously developed for the 1-D case [1] is extended to interpret the radiation mechanism, and compensates the existing gap of array theories. The analysis may naturally reduce to the case of a conventional phased antenna array with radiation focused in its far zone, and exhibits consistent phenomena of plane wave radiations. Theoretical investigations as well as numerical illustrations are presented.