4-Port MIMO Antenna Using Common Radiator on a Flexible Substrate for Sub-1GHz, Sub-6GHz 5G NR, and Wi-Fi 6 Applications

Kumud Ranjan Jha,Z A Pandit Jibran,Chitra Singh,Satish Kumar Sharma

doi:10.1109/ojap.2021.3083932

Abstract

In this paper, an angular symmetric, common radiator coplanar waveguide (CPW) fed four-port multiple-input-multiple-output (MIMO) antenna is designed on a 0.129λ L 2 RT Duroid ( ε r = 3.0, tan δ = 0.001) substrate where λ L is the free space wavelength at the lowest operating frequency ( f L ) of 0.6 GHz. The antenna has a -6 dB impedance bandwidth from 0.6-1.09 GHz, 2.6-3.4 GHz and 4.2-7.0 GHz to cover the emerging wireless communication bands. At the same time, it also has a -10 dB impedance bandwidth extending from 0.7-1.01 GHz, 2.6-3.18 GHz, 5.3-6.06 GHz, and 6.7-6.94 GHz. Design steps to enhance the operating bandwidth and the isolation in the sub-1GHz bands are presented. The antenna has a reasonable realized gain at the simulated and measured frequencies. It exhibits the pattern diversity which is useful for the MIMO implementation. The envelope correlation coefficient (ECC), Mean effective gain (MEG), and the channel capacity of the antenna have been computed from the measured results. In spite of the small circuit size at f L , the ECC ≤ 0.50 over the entire band is observed. In addition to the existing communication applications, this antenna can find newer applications in the emerging 0.6-1.09 GHz band, sub-6GHz 5G near radio (NR), and Wi-Fi 6 communications.

Highlights

T O ENHANCE the wireless data transfer rate to meet the emerging requirements, the multiple-input-multipleoutput (MIMO) system has been proved to be the backbone of the 4th generation (G) and beyond wireless communication systems [1]
The channel capacity can be significantly improved by increasing the number of antenna elements; a four port antenna designed using multi-object optimization technique to operate in 2.5-2.75 GHz and 3.35-3.85-GHz band is reported in [5]
The analysis reveals the effect of the feed length and monopole antenna radius on the operating frequency and percentage change in the frequency with respect to (w.r.t.) the change in ratio of the feed length to radius

Summary

INTRODUCTION

T O ENHANCE the wireless data transfer rate to meet the emerging requirements, the multiple-input-multipleoutput (MIMO) system has been proved to be the backbone of the 4th generation (G) and beyond wireless communication systems [1]. In majority of cases, using the parametric study, these antennas are designed for the ultrawideband (UWB) applications to operate above 2.0 GHz, where wide bandwidth is obtained by controlling overall size of the substrate, radius of the printed monopole, and feed length reduction obtained by increasing the ground plane size. For the quest of larger operating bandwidth and to use it in the MIMO implementation in sub-1GHz band, a single circular printed monopole antenna as a basic building block using CMA technique is analyzed . It shows that by suitably selecting the Lf/R1 where R1 is the radius of the printed circular monopole, f M1 and f can be controlled to meet the intended design requirements. In this type of the antenna, the stub loading along with the lumped capacitance can be used to increase the operating bandwidth in sub-1GHz range

FOUR PORT MIMO ANTENNA DESIGN

ISOLATION IMPROVEMENT

RADIATION CHARACTERISTICS

STATE OF THE ART COMPARISON

Findings

CONCLUSION