A very-low-profile, decoupled, hybrid two-antenna system top-loaded with a coupled strip resonator for isolation enhancement is demonstrated. Each hybrid antenna consists of one 2.4 GHz open slot and one 5 GHz monopole, formed on the two sides of the substrate. The two-antenna design is able to operate in the 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) wireless local area network (WLAN) bands and yet merely occupies a size of 5 mm × 40 mm (about 0.04λ × 0.32λ at 2.4 GHz). The loaded strip resonator is employed to reduce the mutual coupling in the 2.4 GHz band. With further capacitively grounding the decoupling strip using a grounded T strip, good isolation > 18 dB over the 5 GHz bands can also be achieved. Owing to its low profile of 5 mm, the proposed design can find some practical applications in the narrow-bezel notebook computers and is of the smallest footprint among those two 2.4/5 GHz antennas for notebook applications.
2. Khorov, E., A. Kiryanov, A. Lyakhov, and G. Bianchi, "A tutorial on IEEE 802.11ax high efficiency WLANs," IEEE Comm Surveys & Tutorials, Vol. 21, 197-216, 2019. doi:10.1109/TAP.2008.2005460
3. 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. doi:10.1002/mop.24831
4. Kang, T. W. and K. L. Wong, "Isolation improvement of 2.4/5.2/5.8 GHz WLAN internal laptop computer antennas using dual-band strip resonator as a wavetrap," Microwave Opt. Technol. Lett., Vol. 52, 58-64, 2010. doi:10.1109/LAWP.2014.2345776
5. Guo, L., Y. Wang, Z. Du, Y. Gao, and D. Shi, "A compact uniplanar printed dual-antenna operating at the 2.4/5.2/5.8 GHz WLAN bands for laptop computers," IEEE Antennas Wireless Propagat. Lett., Vol. 13, 229-232, 2014. doi:10.1109/LAWP.2015.2394473
6. Liu, Y., Y. Wang, and Z. Du, "A broadband dual-antenna system operating at the WLAN/WiMax bands for laptop computers," IEEE Antennas Wireless Propagat. Lett., Vol. 14, 1060-1063, 2015.
7. Chen, W. S., J. H. Shu, and C. Y. D. Sim, "Small-size WLAN/5G MIMO antenna for laptop computer applications," Asia-Pacific Conference on Antennas and Propagat., 1-3, Xi'an, China, 2017. doi:10.1109/LAWP.2017.2713986
8. 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. doi:10.1109/LAWP.2018.2858849
9. Su, S. W., C. T. Lee, and S. C. Chen, "Very-low-profile, triband, two-antenna system for WLAN notebook computers," IEEE Antennas Wireless Propagat. Lett., Vol. 17, 1626-1629, 2018. doi:10.1002/mop.31156
10. Su, S. W., "Very-low-profile, 2.4/5-GHz WLAN monopole antenna for large screen-to-body-ratio notebook computers," Microwave Opt. Technol. Lett., Vol. 60, 1313-1318, 2018. doi:10.1109/ACCESS.2018.2794606
11. 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. doi:10.2528/PIERM18061904
12. Su, S. W., "Capacitor-inductor-loaded, small-sized loop antenna for WLAN notebook computers," Progress In Electromagnetics Research M, 179-188, 2018.
13. Pozar, D. M., Microwave Engineering, 3rd Ed., Chapter 3, 143-145, Wiley, New York, 2005.