This paper presents a dual-band eight-element multiple-input multiple-output (MIMO) antenna for 5G applications. The 8-element antenna is formed into two 4×4 MIMO systems that operate at 2500-2600 MHz and 1800-2200 MHz bands. The antenna elements are mounted along the perimeter of a rectangular ground plane with a total size of 110 × 80 mm2 and are printed on both sides of a low-profile PCB material. Elements radiate through open rectangular slots etched on the antenna's ground conductor. The open slots are excited by T-shaped microstrip lines fed by 50-Ω coaxial connectors. The size of the ground plane's slots, and the T-shaped radiators control the resonance of the antenna's elements. The proposed design employs orthogonal elements to mitigate mutual coupling. The isolation between ports is less than -10 dB. The radiation efficiency ranges from 40% to 65% across operating frequency bands.
2., "Sub 1 GHz spectrum for LTE and 5G," GSA, 2019. [Online]. Available: https://gsacom.com/paper/sub-1-ghz-spectrum-for-lte-and-5g/. [Accessed: 03-Apr-2020]..
3. Li, Y., C.-Y.-D. Sim, Y. Luo, and G. Yang, "High-isolation 3.5 GHz eight-antenna MIMO array using balanced open-slot antenna element for 5G smartphones," IEEE Trans. Antennas Propag., Vol. 67, No. 6, 3820-3830, Jun. 2019.
4. Zhao, A. and Z. Ren, "Size reduction of self-isolated MIMO antenna system for 5G mobile phone applications," IEEE Antennas Wirel. Propag. Lett., Vol. 18, No. 1, 152-156, Jan. 2019.
5. Li, Y., C.-Y.-D. Sim, Y. Luo, and G. Yang, "Multiband 10-antenna array for sub-6 GHz MIMO applications in 5-G smartphones," IEEE Access, Vol. 6, 28041-28053, 2018.
6. Zhao, A. and Z. Ren, "Wideband MIMO antenna systems based on coupled-loop antenna for 5G N77/N78/N79 applications in mobile terminals," IEEE Access, Vol. 7, 93761-93771, 2019.
7. Ren, Z. and A. Zhao, "Dual-band MIMO antenna with compact self-decoupled antenna pairs for 5G mobile applications," IEEE Access, Vol. 7, 82288-82296, 2019.
8. Cui, L., J. Guo, Y. Liu, and C.-Y.-D. Sim, "An 8-element dual-band MIMO antenna with decoupling stub for 5G smartphone applications," IEEE Antennas Wirel. Propag. Lett., Vol. 18, No. 10, 2095-2099, Oct. 2019.
9. Jiang, W., Y. Cui, B. Liu, W. Hu, and Y. Xi, "A dual-band MIMO antenna with enhanced isolation for 5G smartphone applications," IEEE Access, Vol. 7, 112554-112563, 2019.
10. Chattha, H. T., "4-port 2-element MIMO antenna for 5G portable applications," IEEE Access, Vol. 7, 96516-96520, 2019.
11. Huang, D., Z. Du, and Y. Wang, "A quad-antenna system for 4G/5G/GPS metal frame mobile phones," IEEE Antennas Wirel. Propag. Lett., Vol. 18, No. 8, 1586-1590, Aug. 2019.
12. Wei, G. and Q. Feng, "Dual-band MIMO antenna array for compact 5G smartphones," Progress In Electromagnetics Research C, Vol. 99, 157-165, 2020.
13. Wang, H., R. Zhang, Y. Luo, and G. Yang, "Compact eight-element antenna array for triple-band MIMO operation in 5G mobile terminals," IEEE Access, Vol. 8, 19433-19449, 2020.
14. Parchin, N. O., et al., "Eight-element dual-polarized MIMO slot antenna system for 5G smartphone applications," IEEE Access, Vol. 7, 15612-15622, 2019.
15. Sun, L., H. Feng, Y. Li, and Z. Zhang, "Compact 5G MIMO mobile phone antennas with tightly arranged orthogonal-mode pairs," IEEE Trans. Antennas Propag., Vol. 66, No. 11, 6364-6369, Nov. 2018.
16. Ren, Z., S. Wu, and A. Zhao, "Triple band MIMO antenna system for 5G mobile terminals," 2019 International Workshop on Antenna Technology (iWAT), 163-165, 2019.
17. Hussain, R., A. T. Alreshaid, S. K. Podilchak, and M. S. Sharawi, "Compact 4G MIMO antenna integrated with a 5G array for current and future mobile handsets," IET Microwaves, Antennas Propag., Vol. 11, No. 2, 271-279, Jan. 2017.
18. Ban, Y. L., C. Li, C. Y. D. Sim, G. Wu, and K. L. Wong, "4G/5G multiple antennas for future multi-mode smartphone applications," IEEE Access, 2016.
19. Sharawi, M. S., M. Ikram, and A. Shamim, "A two concentric slot loop based connected array MIMO antenna system for 4G/5G terminals," IEEE Trans. Antennas Propag., Vol. 65, No. 12, 6679-6686, Dec. 2017.
20. CST studio suite, Dassault Syst`emes, 2019. [Online]. Available: www.cst.com. [Accessed: 03-Apr-2020]..
21. Stein, S., "On cross coupling in multiple-beam antennas," IRE Trans. Antennas Propag., Vol. 10, No. 5, 548-557, Sep. 1962.
22. Aziz, H. S. and D. K. Naji, "Printed 5G MIMO antenna arrays in smartphone handset for LTE bands 42/43/46 applications," Progress In Electromagnetics Research M, Vol. 90, 167-184, 2020.
23. H. S. Aziz, D. K. Naji, "Compact dual-band MIMO antenna system for LTE smartphone applications," Progress In Electromagnetics Research C, Vol. 102, 13-30, 2020.