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

• Published in: IEEE Open Journal of Antennas and Propagation Vol. 2; pp. 689 - 701
• Main Authors: Jha, Kumud Ranjan, Jibran, Z. A. Pandit, Singh, Chitra, Sharma, Satish Kumar
• Format: Journal Article
• Language: English
• Published: IEEE 2021
• Subjects: 0.6 GHz; 5G mobile communication; Antenna feeds; Antennas; Bandwidth; Coplanar waveguides; IEEE 802.11ax Standard; integrated antenna; MIMO communication; pattern diversity; sub-7GHz
• ISSN: 2637-6431; 2637-6431
• DOI: 10.1109/OJAP.2021.3083932

In this paper, an angular symmetric, common radiator coplanar waveguide (CPW) fed four-port multiple-input-multiple-output (MIMO) antenna is designed on a <inline-formula> <tex-math notation="LaTeX">0.129\lambda _{\mathrm{ L}}^{2} </tex-math></inline-formula> RT Duroid (<inline-formula> <tex-math notation="LaTeX">\varepsilon _{\mathrm{ r}} =3.0 </tex-math></inline-formula>, tan<inline-formula> <tex-math notation="LaTeX">\delta =0.001 </tex-math></inline-formula>) substrate where <inline-formula> <tex-math notation="LaTeX">\lambda _{\mathrm{ L}} </tex-math></inline-formula> is the free space wavelength at the lowest operating frequency (<inline-formula> <tex-math notation="LaTeX">{f} _{\mathrm{ L}} </tex-math></inline-formula>) 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 <inline-formula> <tex-math notation="LaTeX">{f} _{\mathrm{ L}} </tex-math></inline-formula>, 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.