Design and characterization of a compact single-layer multibeam array antenna using an 8×8 Butler matrix for 5G base station applications

Authors : Intan Izafına IDRUS, Tarık Abdul LATEF, Narendra Kumar ARIDAS, Mohamad Sofıan Abu TALIP, Yoshıhıde YAMADA, Tengku Faız Tengku Mohmed Noor IZAM, Tharek Abd RAHMAN

Pages : 1121-1134

Doi:10.3906/elk-1907-119

View : 21 | Download : 11

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A multibeam array antenna employing a Butler matrix is a promising solution for fifth generation 5G base stations. Due to inaccurate phase differences between output ports in the Butler matrix, the radiation characteristics could show incorrect main beam directions. In addition, the literature has also reported the issue of high amplitude imbalance in the Butler matrix. This paper presents a single-layer multibeam array antenna fed by an 8×8 Butler matrix operating at 28 GHz for 5G base station applications` a more cost-effective solution for large-scale production. The Butler matrix consists of twelve quadrature hybrids, sixteen crossovers, and eight phase shifters. This circuit was integrated with eight antenna elements at the output ports of the Butler matrix. The proposed multibeam array antenna was fabricated using a low dielectric constant and a low loss tangent substrate. The dimensions of the multibeam array antenna were 88×106×0.254~mm$^3$ . The Butler matrix achieved low insertion losses and low phase error with average values of 2.5 dB and less than ±10 ? at 28 GHz, respectively. The measured return losses were less than $\pm10^\circ$ dB at 28 GHz. The measured radiation patterns were obtained and eight main beams were pointed at ±6 $\pm18^\circ$ $\pm30^\circ$ and $\pm44^\circ$ with measured gains between 9 dBi and 14 dBi.
Keywords : Base station, Butler matrix, fifth generation, 5G, multibeam array antenna, single layer