This paper presents a MIMO antenna system composed of eight wideband horizontal dual-loop antenna elements. Each dual-loop antenna is printed on both sides of a smartphone board. The unit element antenna is designed to operate in the frequency range from 3.2 GHz to 5 GHz. The performance of the MIMO system is then analyzed. The performance of the obtained MIMO system in the frequency range from 3.2 GHz to 4.8 GHz is characterized by input reflection coefficient which is less than -6 dB for all antenna elements, and the isolation between the elements is larger than 15 dB. The total efficiency is greater than 55% over the entire band (3.2-4.8 GHz). Parameters of the multichannel antennas including envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CLL) are analyzed to evaluate the performance of the MIMO system. The effect of the human hand and head on the performance of this MIMO antenna is also investigated. In addition, the effect of the radiated fields on the human body is also studied. The Specific Absorption Rate (SAR) value is found to be less than 0.8 W/kg. The MIMO system antenna is fabricated and measured. Good agreements are obtained between the simulated and measured parameters. The proposed MIMO system is applicable to the 5G N48, N77, and N78 bands.
Walaa M. Hassan,
Khalid Moustafa Ibrahim,
Ahmed Mohamed Attiya,
"MIMO Antenna for N48, N77, N78 5G Applications," Progress In Electromagnetics Research C,
Vol. 117, 129-143, 2021. doi:10.2528/PIERC21092605
1. Mak, K. M., H. W. Lai, K. M. Luk, and C. H. Chan, "Circularly polarized patch antenna for future 5G mobile phones," IEEE Access, Vol. 2, 1521-1529, Jan. 2015.
2. Al-Dulaimi, A., S. Al-Rubaye, Q. Ni, and E. Sousa, "5G communications race: Pursuit of more capacity triggers LTE in unlicensed band," IEEE Vehicular Technology Magazine, Vol. 10, No. 1, 43-51, Mar. 2015. doi:10.1109/MVT.2014.2380631
3. Chen, X., S. Shoaib, I. Shoaib, N. Shoaib, and C. G. Parini, "MIMO antennas for mobile handsets," IEEE Antennas and Wireless Propagation Letters, Vol. 14, 799-802, 2015.
4. 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, Vol. 4, 2981-2988, 2016. doi:10.1109/ACCESS.2016.2582786
5. Li, M. Y., Z. Q. Xu, Y. L. Ban, C. Y. D. Sim, and Z. F. Yu, "Eight-port orthogonally dual-polarised MIMO antennas using loop structures for 5G smartphone," IET Microw., Antennas Propag., Vol. 11, 1810-1816, Dec. 2017. doi:10.1049/iet-map.2017.0230
7. Tsai, C.-Y., K.-L. Wong, and W.-Y. Li, "Experimental results of the multi-Gbps smartphone with 20 multi-input multi-output (MIMO) antennas in the 20-12 MIMO operation," Microw. Opt. Technol. Lett., Vol. 60, 20012010, Aug. 2018.
8. Wong, K.-L., C.-Y. Tsai, and J.-Y. Lu, "Two asymmetrically mirrored gap-coupled loop antennas as a compact building block for eight-antenna MIMO array in the future smartphone," IEEE Trans. Antennas Propag., Vol. 65, No. 4, 1765-1778, Apr. 2017. doi:10.1109/TAP.2017.2670534
9. Deng, J. Y., J. Yao, D. Q. Sun, and L. X. Guo, "Ten-element MIMO antenna for 5G terminals," Microw. Opt. Technol. Lett., Vol. 60, 3045-3049, Dec. 2018. doi:10.1002/mop.31404
10. Wong, K. L., B. W. Lin, and W.-Y. Li, "Dual-band dual inverted-F/loop antennas as a compact decoupled building block for forming eight 3.5/5.8-GHz MIMO antennas in the future smartphone," Microw. Opt. Technol. Lett., Vol. 59, 2715-2721, Nov. 2017.
11. Guo, J., L. Cui, C. Li, and B. Sun, "Side-edge frame printed eight-port dual-band antenna array for 5G smartphone applications," IEEE Trans. Antennas Propag., Vol. 66, 7412-7417, Dec. 2018. doi:10.1109/TAP.2018.2872130
12. Li, Y., C. Y. D. Sim, Y. Luo, and G. Yang, "12-port 5G massive MIMO antenna array in sub-6 GHz mobile handset for LTE bands 42/43/46 applications," IEEE Access, Vol. 6, 344-354, Feb. 2018. doi:10.1109/ACCESS.2017.2763161
13. 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, Jun. 2018. doi:10.1109/ACCESS.2018.2838337
14. Xu, H., H. Zhou, S. Gao, H. Wang, and Y. Cheng, "Multimode decoupling technique with independent tuning characteristic for mobile terminals," IEEE Trans. Antennas Propag., Vol. 65, No. 12, 6739-6751, Dec. 2017. doi:10.1109/TAP.2017.2754445
15. Sun, L. B., 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. doi:10.1109/TAP.2018.2864674
16. Zhao, A. and Z. Ren, "Multiple-input and multiple-output antenna system with self-isolated antenna element for fth-generation mobile terminals," Microw. Opt. Technol. Lett., No. 61, 20-27, Jan. 2019. doi:10.1002/mop.31515
17. Li, M.-Y., Y.-L. Ban, Z.-Q. Xu, J. Guo, and Z.-F. Yu, "Tri-polarized 12-antenna MIMO array for future 5G smartphone applications," IEEE Access, Vol. 6, 6160-6170, Jan. 2018. doi:10.1109/ACCESS.2017.2781705
18. Zhao, A. and Z. Ren, "Size reduction of self-isolated MIMO antenna system for 5G mobile phone applications," IEEE Antennas Wireless Propag. Lett., Vol. 18, No. 1, 152-156, Jan. 2019. doi:10.1109/LAWP.2018.2883428
20. Sharawi, M. S., "Printed multi-band MIMO antenna systems and their performance metrics [wireless corner]," IEEE Antennas and propagation Magazine, Vol. 55, No. 5, 218-232, 2013. doi:10.1109/MAP.2013.6735522
21. Khali, M., S. Naqvi, N. Hussain, M. Rahman, S. Mirjavadi, et al. "4-Port MIMO antenna with defected ground structure for 5G millimeter wave applications," Electronics, Vol. 9, 2020.
22., "IEEE standards for safety levels with request to human exposure to radiofrequency electromagnetic fields, 3 kHz to 300 GHz,", IEEE Std. C95.1, 1999.
23. ICNIRP (International Commission on Non-Ionizing Radiation Protection), "Guidelines for limiting exposure to time-varying electric magnetic, and electromagnetic fields (up to 300 GHz)," Health Phys., Vol. 74, 494-522, 1998.
24. Zou, H., Y. Li, C.-Y.-D. Sim, and G. Yang, "Design of 8_8 dual-band MIMO antenna array for 5G smartphone applications," Int. J. RF Microw. Comput. Aided Eng., Vol. 28, No. 9, Art. No. e21420, Nov. 2018.
25. 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, Vol. 4, 2981-2988, 2016. doi:10.1109/ACCESS.2016.2582786
26. Wong, K. L., J. Y. Lu, L. Y. Chen, W. Y. Li, and Y. L. Ban, "8-antenna and 16-antenna arrays using the quad-antenna linear array as a building block for the 3.5-GHz LTE MIMO operation in the smart-phone," Microw Opt Technol Lett., Vol. 58, 174-18, 2016. doi:10.1002/mop.29527
27. Wong, K. L., C. Y. Tsai, and J. Y. Lu, "Two asymmetrically mirrored gap-coupled loop antennas as a compact building block for eight-antenna MIMO array in the future smartphone," IEEE Trans. Antennas Propag., Vol. 65, 1765-1778, 2017. doi:10.1109/TAP.2017.2670534
28. Guo, J. L., L. Cui, C. Li, and B. H. Sun, "Side-edge frame printed eight-port dual-band antenna array for 5G smartphone applications," IEEE Trans. Antennas Propag., Vol. 66, No. 12, 7412-7417, Dec. 2018. doi:10.1109/TAP.2018.2872130
29. Cui, L., J. Guo, Y. Liu, and C.-Y.-D. Sim, "An 8-element dualband MIMO antenna with decoupling stub for 5G smartphone applications," IEEE Antennas Wireless Propag. Lett., Vol. 18, No. 10, 2095-2099, 2019. doi:10.1109/LAWP.2019.2937851