In this paper, a novel low-profile and dual-polarized antenna is presented. The antenna is composed of two pairs of rhombic dipoles excited by two orthogonal baluns. The broadband characteristic is achieved by introducing a metal ring under the rhombic dipole, and the radiation pattern beam widths are also improved. Based on the antenna unit, a 2-element antenna array is designed, fabricated, and measured. The relative bandwidth (standing wave less than 1.5) of the antenna is 45.1%, and the port isolation is greater than 27 dB, whereas the cross-polarization level maintains lower than 16 dB in the the frequency band of 2.4-3.8 GHz. The measured results are in good agreement with the simulated ones. This proposed antenna also has low profile characteristics, and the profile height is 20.8 mm, which is less than one quarter of the wavelength (24.2 mm) of the central frequency point (f = 3.1 GHz).
2. Cui, Y., R. Li, and H. Fu, "A broadband dual-polarized planar antenna for 2G/3G/LTE base stations," IEEE Trans. Antennas Propag., Vol. 62, No. 9, 4836-4840, Sep. 2014.
3. Li, M. and K. M. Luk, "Wideband magnetoelectric dipole antennas with dual polarization and circular polarization," IEEE Antennas Propag. Mag., Vol. 57, No. 1, 110-119, Feb. 2015.
4. Zhang, Q. and Y. Gao, "A compact broadband dual-polarized antenna array for base stations," IEEE Antennas Wireless Propag. Lett., Vol. 17, No. 6, 1073-1076, Jun. 2018.
5. He, Y., Z. Pan, X. Cheng, Y. He, J. Qiao, and M. M. Tentzeris, "A novel dual-band, dual-polarized, miniaturized and low-profile base station antenna," IEEE Trans. Antennas Propag., Vol. 63, No. 12, 5399-5408, Dec. 2015.
6. Ding, C., H. Sun, R. W. Ziolkowski, and Y. J. Guo, "A dual layered loop array antenna for base stations with enhanced cross-polarization discrimination," IEEE Trans. Antennas Propag., Vol. 66, No. 12, 6975-6985, Dec. 2018.
7. Qin, P., L. Ji, S. Chen, and Y. J. Guo, "Dual-polarized wideband Fabry-Perot antenna with quadlayer partially reflective surface," IEEE Antennas Wireless Propag. Lett., Vol. 17, No. 4, 551-554, Apr. 2018.
8. Huang, H., Y. Liu, and S. Gong, "A dual-broadband, dual-polarized base station antenna for 2G/3G/4G applications," IEEE Antennas Wireless Propag. Lett., Vol. 16, 1111-1114, Nov. 2016.
9. He, Y., W. Tian, and L. Zhang, "A novel dual-broadband dual-polarized electrical downtilt base station antenna for 2G/3G applications," IEEE Access, Vol. 5, 15241-15249, 2017.
10. Chu, Q. X., D. Wen, and Y. Luo, "A broadband ±45◦ dual-polarized antenna with Y-shaped feeding lines," IEEE Trans. Antennas Propag., Vol. 63, 483-490, Feb. 2015.
11. Liu, Y., J. Wang, and S. Gong, "Low-profile dual-polarized planar antenna with compact structure for base stations," Chin. J. Electron., Vol. 26, 1092-1095, 2017.
12. Zhai, H., K. Zhang, S. Yang, and D. Feng, "A low-profile dual-band dual-polarized antenna with an AMC surface for WLAN applications," IEEE Antennas Wireless Propag. Lett., Vol. 16, 2692-2695, 2017.
13. Li, M., Q. L. Li, B. Wang, C. F. Zhou, and S. W. Cheung, "A low profile dual-polarized dipole antenna using wideband AMC reflector," IEEE Trans. Antennas Propag., Vol. 66, No. 5, 2610-2615, May 2018.
14. Feresidis, A. P., G. Goussetis, S. Wang, and J. C. Vardaxoglou, "Artificial magnetic conductor surfaces and their application to low-profile high-gain planar antennas," IEEE Trans. Antennas Propag., Vol. 53, No. 1, 209-215, Jan. 2005.
15. Li, M., K. M. Luk, L. Ge, and K. Zhang, "Miniaturization of magnetoelectric dipole antenna by using metamaterial loading," IEEE Trans. Antennas Propag., Vol. 64, No. 11, 4914-4918, Nov. 2016.