Beam-forming circuits for multibeam antenna array

Considered in this paper is the feed system for passive RF transmission line. The general feed system for connecting 2ⁿ inputs with 2ⁿ elements is presented. It consists of conventional hybrid junctions with associated phase shifters. In order to increase the possible number of elements in the array, it is necessary to find applicable junctions, which are more complex than the hybrid ones. 3-input/output junctions, as well as 4-input/output junctions are presented. They are used in multiple feed networks, expanding the number of elements in the array up to 2^L3^M4^N.