A miniaturized in size linear multiple-input multiple-output (MIMO) antenna array operating on demand at 28 GHz and 24.8 GHz for 5G applications is presented and investigated in this research work. The antenna array has the capability to switch and operate efficiently from 28 GHz to 24.8 GHz with more than 15 dB gain at each frequency, having 2.1 GHz and 1.9 GHz bandwidth, respectively. The unit cell of the proposed antenna array consists of a transmission line (TL) fed circular patch connected with horizontal and vertical stubs. The vertical stubs are used to switch the operating frequency and mitigate the unwanted interaction between the adjacent elements of the antenna array to miniaturize the overall dimension of the array. The proposed antenna array is compared with the recent works published in the literature for 5G applications to demonstrate the features of miniaturization and high gain. The proposed array is a potential candidate for 5G sensors applications like cellular devices, drones, biotelemetry sensors, etc.
2. Naqvi, A. H. and S. Lim, "Review of recent phased arrays for millimeter-wave wireless communication," Sensors, Vol. 18, No. 10, 3194, 2018.
3. Federal Communications Commission (FCC), , FCC Establishes Procedures for First 5G Spectrum Auctions, Aug. 2018.
4. Yang, B., Z. Yu, J. Lan, R. Zhang, J. Zhou, and W. Hong, "Digital beamforming-based massive MIMO transceiver for 5G millimeter-wave communications," IEEE Trans. Microw. Theory Tech., 1-16, 2018.
5. Rappaport, T. S., S. Sun, R. Mayzus, H. Zhao, Y. Azar, K. Wang, G. N. Wong, J. K. Schulz, M. Samimi, and F. Gutierrez, "Millimeter wave mobile communications for 5G cellular: It will work!," IEEE Access, Vol. 1, 335-349, 2013.
6. Dehos, C., J. González, A. Domenico, D. Kténas, and L. Dussopt, "Millimeter-wave access and backhauling: The solution to the exponential data traffic increase in 5G mobile communications systems?," IEEE Commun. Mag., Vol. 52, 88-95, 2014.
7. Jamaluddin, M. H., M. Kamarudin, and M. Khalily, "Rectangular dielectric resonator antenna array for 28 GHz applications," Progress in Electromagnetics Research, Vol. 63, 53-61, 2016.
8. Yashchyshyn, Y., et al., "28 GHz switched-beam antenna based on S-PIN diodes for 5G mobile communications," IEEE Antennas Wirel. Propag. Lett., Vol. 17, No. 2, 225-228, 2018.
9. Bang, J., et al., "A SAR reduced MM-wave beam-steerable array antenna with dual-mode operation for fully metal-covered 5g cellular handsets," IEEE Antennas Wirel. Propag. Lett., 2018.
10. Li, W. T., M. Wei, B. Badamchi, H. Subbaraman, and X. Shi, "A novel tri-band reconfigurable microstrip patch antenna," Frequenz, Vol. 74, No. 7-8, 247-253, 2020.
11. Yu, B., et al., "A novel 28 GHz beam steering array for 5G mobile device with metallic casing application," IEEE Trans. Antennas Propag., Vol. 66, No. 1, 462-466, 2018.
12. Sodré, Jr., A. C., I. F. da Costa, R. A. dos Santos, H. R. D. Filgueiras, and D. H. Spadoti, "Waveguide-based antenna arrays for 5G networks," International Journal of Antennas and Propagation, Vol. 2018, Article ID 5472045, 10 pages, 2018.
13. Ullah, H. and F. A. Tahir, "A broadband wire hexagon antenna array for future 5G communications in 28 GHz band," Microw. Opt. Technol. Lett., 1-6, 2018.
14. Mao, C., M. Khalily, P. Xiao, T. W. C. Brown, and S. Gao, "Planar sub-millimeter-wave array antenna with enhanced gain and reduced sidelobes for 5G broadcast applications," IEEE Trans. Antennas Propag., Vol. 67, No. 1, 160-168, Jan. 2019.
15. Jilani, S. F., et al., "Millimetre-wave T-shaped MIMO antenna with defected ground structures for 5G cellular networks," IET Microw. Antennas Propag., Vol. 12, No. 5, 672-677, 2018.
16. Zhang, J., X. Ge, Q. Li, M. Guizani, and Y. Zhang, "5G millimeter-wave antenna array: Design and challenges," IEEE Wirel. Commun., Vol. 24, 106-112, 2017.
17. Hong, W., et al., "Study and prototyping of practically large-scale mmWave antenna systems for 5G cellular devices," IEEE Commun. Mag., Vol. 52, No. 9, 63-69, 2014.
18. Roh, W., et al., "Millimeter-wave beamforming as an enabling technology for 5G cellular communications: Theoretical feasibility and prototype results," IEEE Commun. Mag., Vol. 52, No. 2, 106-113, 2014.
19. Naqvi, S. A. and M. S. Khan, "Design of a miniaturized frequency reconfigurable antenna for rectenna in WiMAX and ISM frequency bands," Microw. Opt. Technol. Lett., Vol. 60, 325-330, 2018.
20. Awan, W. A., A. Zaidi, N. Hussain, A. Iqbal, and A. Baghdad, "Stub loaded, low profile UWB antenna with independently controllable notch-bands," Microw. Opt. Technol. Lett., 1-8, 2019.
21. Naqvi, S. A., "Miniaturized triple band and ultra-wideband (UWB) fractal antennas for UWB applications," Microw. Opt. Technol. Lett., Vol. 59, 1542-1546, 2017.
22., "Rogers Corporation,", www.rogerscorp.com, accessed Feburary 2021.
23. Balanis, C. A., Antenna Theory-Analysis and Design, Wiley, 1997.
24. Ansys HFSS, ver. 2016.2, Ansys Corporation, Pittsburgh, PA, 2017.
25., "MACOM,", www.macom.com, accessed Feburary 2021.
26. Ta, S. X., H. Choo, and I. Park, "Broadband printed-dipole antenna and its arrays for 5G applications," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 2183-2186, 2017.
27. Hussain, N., et al., "Compact wideband patch antenna and its MIMO configuration for 28 GHz applications," AEU-International Journal of Electronics and Communications, Vol. 132, e153612, 2021.