Improved Butler Matrix configuration for smart beamforming operations

In this work the authors propose a Butler Matrix (BM) based beamforming network (BFN) that feeds a linear antenna array. A BM 8×8 is integrated with a specific Switching Network (SN) and a group of Switched-Line Phase Shifters (SLPS), in order to properly drive the excitation of the antenna elements. The resulting configuration provides enhanced beamforming flexibility compared to a Switched Beam System (SBS) fed by a typical BM. Thus, a smart beamforming structure can be designed that combines the simplicity of a SBS with some of the advantages of an Adaptive Array System (AAS).