The aim of this work is to provide a miniaturπized antenna pair, which has a smallest size of 5 mm × 25 mm (about 0.04λ × 0.20λ at 2.4 GHz) among the recent laptop antennas and yet is capable of 2.4/5/6 GHz Wi-Fi 6E operation with acceptable isolation. The antenna pair comprises two small and symmetrical antenna units. Each unit is identical in geometry and has a coupling strip and a parasitic strip with an in-series inductor. The back-to-back unit arrangement helps better isolation in the 2.4 GHz band. A decoupling coupled strip is introduced between the units with a 5 mm spacing. This floating strip of a half wavelength at about 5.36 GHz attracts the surface currents of one unit excited in the 5/6 GHz bands, which in turn helps much decreased currents entering the port of the other unit. As a result, enhanced isolation can also be achieved in the upper bands.
2. Wi-Fi Alliance, Wi-Fi Alliance brings Wi-Fi 6 into 6 GHz, https://www.wi-fi.org/news-events/newsroom/wi-fi-alliance-brings-wi-fi-6-into-6-ghz.
3. Wireless Broadband Alliance, WBA's first phase of Wi-Fi 6E trials shows the massive potential of Wi-Fi in the 6 GHz band, https://www.realwire.com/releases/WBAs-First-Phase-of-Wi-Fi-6E-Trials-Shows-the-Massive-Potential-of-Wi-Fi.
4. Su, S. W. and C. C. Wan, "Asymmetrical, self-isolated laptop antenna in the 2.4/5/6 GHz Wi-Fi 6E bands," Proc. Int. Symposium on Antennas and Propagat., 1-2, Taipei, Taiwan, 2021.
5. Su, S. W., D. P. Yusuf, and F. H. Chu, "Conjoined, Wi-Fi 6E MIMO antennas for laptops," Proc. Int. Symposium on Antennas and Propagat., 1-2, Taipei, Taiwan, 2021.
6. Su, S. W., "Compact, small, chip-inductor-loaded Wi-Fi 6E monopole antenna," IEEE Int. Symposium on Antennas and Propagat., 1-2, Singapore, 2021.
7. Su, S. W., C. T. Lee, and S. C. Chen, "Compact, printed, tri-band loop antenna with capacitively-driven feed and end-loaded inductor for notebook computers," IEEE Access, Vol. 6, 6692-6699, 2018.
8. Mak, A. C. K., C. R. Rowell, and R. D. Murch, "Isolation enhancement between two closely packed antennas," IEEE Trans. Antennas Propagat., Vol. 56, 3411-3419, 2008.
9. Su, S. W., "Very-low-profile, 2.4/5-GHz WLAN monopole antenna for large screen-to-body-ratio notebook computers," Microw. Opt. Technol. Lett., Vol. 60, 1313-1318, 2018.
10. Su, S. W., "Capacitor-inductor-loaded, small-sized loop antenna for WLAN notebook computers," Progress In Electromagnetics Research M, Vol. 71, 179-188, 2018.
11. Su, S. W., "Very-low-profile, small-sized, printed monopole antenna for WLAN notebook computer applications," Progress In Electromagnetics Research Letters, Vol. 82, 51-57, 2019.
12. Deng, J. Y., J. Y. Li, L. Zhao, and L. X. Guo, "A dual-band inverted-F MIMO antenna with enhanced isolation for WLAN applications," IEEE Antennas Wireless Propagat. Lett., Vol. 16, 2270-2273, 2017.
13. Su, S. W., C. T. Lee, and Y. W. Hsiao, "Compact two-inverted-F-antenna system with highly integrated π-shaped decoupling structure," IEEE Trans. Antennas Propagat., Vol. 67, 6182-6186, 2019.
14. Su, S. W. and Y. W. Hsiao, "Small-sized, decoupled two-monopole antenna system using the same monopole as decoupling structure," Microw. Opt. Technol. Lett., Vol. 61, 2049-2055, 2019.
15. Chang, W. H. and S. W. Su, "Very-low-profile, decoupled, hybrid, two-antenna system using top-loaded, coupled strip resonator for notebook computer applications," Progress In Electromagnetics Research M, Vol. 84, 63-72, 2019.
16. Chen, Y.-R. and W.-S. Chen, "Design of MIMO WLAN 2.4/5.2/5.8 and 5G sub-6 GHz antennas for laptop computer applications," IEEE Int. Workshop on Electromagnetics, 1-2, Penghu, Taiwan, 2020.
17. Ansys HFSS, Ansys Inc., , http://www.ansys.com/Products/Electronics/ANSYS-HFSS.
18. SG 24-S, MVG, , https://www.mvg-world.com/en/products/antenna-measurement/multi-probe-systems/sg-24.
19. Blanch, S., J. Romeu, and I. Corbella, "Exact representation of antenna system diversity performance from input parameter description," Electronics Lett., Vol. 39, 705-707, 2003.
20. Sharawi, M. S., "Printed multi-band MIMO antenna systems and their performance metrics," IEEE Antennas and Propagat. Mag., Vol. 55, 218-232, 2013.
21. Vaughan, R. G. and J. B. Andersen, "Antenna diversity in mobile communications," IEEE Trans. Vehicular Technol., Vol. 36, 149-172, 1987.
22. Jha, K. R. and S. K. Sharma, "Combination of MIMO antennas for handheld devices," IEEE Antennas and Propagat. Mag., Vol. 60, 118-131, 2018.