Patent ID: 6992622

Claim:
An antenna system for determining the direction of arrival (DOA) of received signals in azimuth and elevation, and forming beams in the determined direction, the system comprising: (a) two antenna arrays, each of the antenna arrays including a plurality of antenna elements; (b) two first stage multi-mode-port matrices in communication with the two antenna arrays, each first stage multi-mode-port matrix including a plurality of interconnecting hybrids for processing azimuth beams; (c) at least one second stage multi-mode-port matrix including a plurality of interconnecting hybrids for processing elevation beams; and (d) a transceiver in communication with the second stage multi-mode-port matrix, wherein: (i) the antenna arrays and the first stage multi-mode-port matrices form a plurality of orthogonal omni-directional modes, (ii) each of the modes has a characteristic phase set, (iii) two of the modes' phases are used to determine DOA in azimuth, and (iv) the second stage multi-mode-port matrix forms an elevation sum-mode and an elevation difference-mode such that DOA of the received signals can be determined in elevation, and beams can be formed in the direction of the received signals.