4×4 narrow-beam Butler matrix fed antenna array design for multibeam operations for wireless application

Abstract

For the coverage of the intended region, narrow beam radiation patterns are required in wireless communication. multiple-input multiple-output (MIMO) and 5G solve the problem of large spectrum, coverage, capacity, and data rates required for the intended user/direction. The presented 4-input 4-output Butler matrix fed antenna array design covers 26.86–29.05 GHz (2.18 GHz bandwidth) and frequency band of 2:1 voltage standing wave ratio (return loss −10 dB). Butler matrix fed antenna array is designed on Rogers RO5880 substrate having a dimension of 48.82 mm × 38.76 mm × 0.254 mm. The research presents design and implementation of a narrow-beam 4×4 Butler matrix fed antenna array to cover −22 degree, 11 degree, −11 degree, and 22 degree directions for the 5G millimeter wave beamforming applications. The proposed design utilizes hybrid couplers, delay lines, crossovers and phase shifters to achieve multiple narrow-beam states. The presented design can be integrated with millimeter wave microwave circuits, arrays, and MIMO-arrays. The presented Butler matrix fed antenna array gain is 14.65 dBi at the radiating ports and at each port simulated radiation efficiency is better than 89.85%.