In order to satisfy the requirements of 2G/3G/4G wireless communication, two kinds of base station antennas with wideband, dual-polarized and three-modes are proposed in this paper. Firstly, a pair of diamond dipoles is placed in an orthogonal way to realize dual-polarizations, then a pair of Y-shaped branches is added to generate a new mode. The Y-type coupling feeding can increase the impedance bandwidth without increasing the size of antenna. The antenna achieves an impedance bandwidth of 51.75% (1.69-2.87 GHz) with a return loss lower than -14 dB. The antenna also has a stable radiation performance. The gain is greater than 8.6 dBi, and the port isolation is less than -27 dB over the entire frequency band. Then based on above antenna, a C-type slot notched antenna is added to improve anti-interference ability. Finally, band stop characteristics are obtained by etching a C-type slot line resonator on two dipoles. The results show that the bandwidth is 1.7-2.69 GHz, and the sharp notched band is 1.8-1.95 GHz. The C-type slot line here can be regarded as a quarter wavelength resonator in series. Moreover, the isolation of the port is less than -28 dB, and the 3 dB beamwidth in the bandwidth is 66±5˚. Both antennas are fabricated and have dual polarizations, simple structure, and good radiation performance, which can be used in the next generation of wireless communication.
2. Xue, Q., S. W. Liao, and J. H. Xu, "A differentially-driven dual-polarized magneto-electric dipole antenna," IEEE Trans. Antennas Propag., Vol. 61, No. 1, 425-430, Jan. 2013.
3. Su, D., J. J. Qian, H. Yang, and D. Fu, "A novel broadband polarization diversity antenna using a cross-pair of folded dipoles," IEEE Antennas Wireless Propag. Lett., Vol. 4, 433-435, 2005.
4. Liu, Y., H. Yi, F. W. Wang, and S. X. Gong, "A novel miniaturized broadband dual-polarized dipole antenna for base station," IEEE Antennas Wireless Propag. Lett., Vol. 12, 1335-1338, 2013.
5. Chu, Q. X. and Y. Luo, "A broadband unidirectional multi-dipole antenna with very stable beamwidth," IEEE Trans. Antennas Propag., Vol. 61, No. 5, 2847-2852, 2013.
6. 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, Sept. 2014.
7. Gou, Y., S. Yang, J. Li, and Z. Nie, "A compact dual-polarized printed dipole antenna with high isolation for wideband base station applications," IEEE Trans. Antennas Propag., Vol. 62, No. 8, 4392-4395, Aug. 2014.
8. Zheng, D.-Z. and Q.-X. Chu, "A multimode wideband ±45° dual-polarized antenna with embedded loops," IEEE Antennas Wireless Propag. Lett., Vol. 16, 633-636, Jul. 2017.
9. Chu, Q. X., D. L. Wen, and Y. Luo, "A broadband ±45° dual-polarized antenna with Y-shaped feeding lines," IEEE Trans. Antennas Propag., Vol. 63, No. 2, 483-490, Feb. 2015.
10. Ngytn, D. T., D. H. Lee, and H. C. Park, "Very compact printed triple band-notched UWB antenna with quarter-wavelength slots," IEEE Antennas Wireless Propag. Lett., No. 11, 411-414, 2012.
11. Seo, Y. S., et al., "Design of trapezoid monopole antenna with band-notched performance for UWB," IET Electronics Letters, Vol. 48, No. 12, 673-674, 2012.
12. Chen, B., et al., "Compact ultra-wideband antenna with reconfigurable notched bands," IET Electronics Letters, Vol. 48, No. 19, 1175-1176, 2012.
13. Liao, X. J., et al., "Aperture UWB antenna with triple band-notched characteristics," IET Electronics Letters, Vol. 47, No. 2, 77-79, 2011.
14. Yazdi, M. and N. Komjani, "Design of a band-notched UWB monopole antenna by means of an EBG structure," IEEE Antennas Wireless Propag. Lett., Vol. 10, 170-173, 2011.
15. Hong, J.-S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Wiley, New York, NY, USA, 2001.
16. Gomez-Calero, C., B. Taha Ahmed, and R. Martinez, "A novel ultrawide band frequency planar notch-filter antenna," Microw. Opt. Technol. Lett., Vol. 52, No. 1, 213-216, Jan. 2010.
17. Zhai, H., J. Zhang, Y. Zang, Q. Gao, and C. Liang, "An LTE base-station magnetoelectric dipole antenna with anti-interference characteristics and its MIMO system application," IEEE Antennas Wireless Propag. Lett., Vol. 14, 906-909, 2015.
18. Huang, H., Y. Liu, and S. Gong, "A broadband dual-polarized base station antenna with anti-interference capability," IEEE Antennas and Wireless Propag. Lett., Vol. 16, 613-616, 2017.
19. Ding, C. F., X. Y. Zhang, Y. Zhang, Y. M. Pan, and Q. Xue, "Compact broadband dual-polarized filtering dipole antenna with high selectivity for base-station applications," IEEE Trans. Antennas Propag., Vol. 66, No. 11, 5747-5756, Nov. 2018.
20. Kraus, J. D. and R. J. Marhefkas, Antennas: For All Applications, 3rd Ed., 165-196, McGrw-Hill, Tempe, AZ, USA, 2002.