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

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 −10 dB at 28 GHz. The measured radiation patterns were obtained and eight main beams were pointed at ±6 • , ±18 • , ±30 • , and ±44 • with measured gains between 9 dBi and 14 dBi.

A compact size wide‐angle 3 × 3 substrate integrate waveguide Butler matrix for Ku‐band applications

“…The return loss of AVA and also the comparison gains of proposed SIW antipodal Vivaldi, with and without lens section are displayed in Figure 2. The proposed SIWAVA can cover all Ku-Band operation frequency range (12)(13)(14)(15)(16)(17)(18). It is clear that, using lens section has not sensible changing in frequency bandwidth, it leads to increase an average 3 dB gain.…”

“…Furthermore, the dependence of the structure performance to the properties of the substrate characteristic variation with respect to frequency (for instance, increment in loss tangent) is another factor that limits the use of microstrip structure. For overcoming these problems, substrate integrated waveguide (SIW) technology is a good solution 15–20 . SIW structures are implemented on PCBs.…”

“…For overcoming these problems, substrate integrated waveguide (SIW) technology is a good solution. [15][16][17][18][19][20] SIW structures are implemented on PCBs. Its emulated waveguide, SIW sidewalls are fabricated from vias rather than the solid fences utilized in traditional waveguides.…”

A low‐power‐consumption massive MIMO scheme based on multibeam antenna array

“…As another method, multibeam antenna array generates multiple beams for different parts of coverage area, with the reduction of computational complexity. Some multibeam antenna arrays with Butler matrix networks have been studied 16–18 . Nevertheless, the previous work focus on the antenna performance with a small size of array.…”

“…Some multibeam antenna arrays with Butler matrix networks have been studied. [16][17][18] Nevertheless, the previous work focus on the antenna performance with a small size of array.…”