Connecting Networks for Two-Dimensional Butler Matrices With Improved Aggregate Gain

The concept of connecting networks for two-dimensional beamforming networks is introduced. It enables to generate a triangular lattice of beams providing an improvement in aggregate gain over conventional Butler matrices. The connecting network is used to rearrange the output ports of a two-dimensional beamformer to produce a planar array with the desired properties. A key feature of the design is the use of a twist matrix which enables to maintain wideband performance. The concept is demonstrated with numerical results at 22 GHz.