A Low-Profile High Isolation Wideband Dual-Polarized Antenna for Sub-1 GHz Base Stations

Year 2024, , 677 - 686, 01.06.2024

Emre Alp Miran , Mehmet Çiydem

https://doi.org/10.35378/gujs.1279556

Abstract

This study introduces a compact, wideband dual-polarized suspended patch antenna designed for LTE700/LTE850/CDMA850/GSM900 applications, with a focus on achieving high isolation. The antenna design has two suspended patches that are excited in orthogonal directions using a modified crossed-slot configuration. The modifications applied to the crossed-slot significantly enhance the −15 dB impedance bandwidth, resulting in improved port isolation between polarizations. Both theoretical analysis and experimental testing confirm these enhancements, revealing an impressive −15 dB impedance bandwidth of 37% (688-1000 MHz) and port isolation exceeding 35 dB in the operating band. The antenna exhibits symmetric and directional radiation patterns in principle planes, with half-power beamwidths ranging from 55.32º to 65.61º and 61.79º to 66.84º. Antenna gain show exhibits variation in the range of 7.3-8.4 dBi across the measured frequencies. The compact size of the antenna, measuring 380 × 380 × 43.6 mm³, makes it highly suitable for integration into commercially deployed base stations. Throughout the paper, we provide a detailed presentation of the antenna's geometry, feeding mechanism, parametric studies, and experimental results. The combined theoretical analysis and practical experimentation validate the success of the proposed antenna design, highlighting its potential for robust performance in a wide range of communication applications.

Keywords

Dual-Polarization, High Isolation, Wideband, Cross-slot Coupling, Base Station Antenna

References

• [1] Mishra, P. K., Jahagirda, D. R., and Kumar, G., “A review of broadband dual linearly polarized microstrip antenna designs with high isolation [education column]”, IEEE Antennas and Propagation Magazine, 56(6): 238–251, (2014).
• [2] Luo, Y., Chu, Q. X., and Wen, D. L., “A ±45º dual-polarized base-station antenna with enhanced cross-polarization discrimination via addition of four parasitic elements placed in a square contour”, IEEE Transactions on Antennas and Propagation, 64(4): 1514–1519, (2016).
• [3] Ding, C., Sun, H., Ziolkowski, R. W., and Guo, Y. J., “Simplified tightly-coupled cross-dipole arrangement for base station applications”, IEEE Access, 5: 27491–27503, (2017).
• [4] Zhao, Y., Rakluea, C., Hongnara, T., and Chaimool, S., “A compact dual-broadband multiple-input multiple-output (MIMO) indoor base station antenna for 2G/3G/LTE systems”, IEEE Access, 7: 82238–82245, (2019).
• [5] Dai, X. W., Wang, Z. Y., Liang, C. H., Chen, X., and Wang, L. T., “Multiband and dual-polarized omnidirectional antenna for 2G/3G/LTE application”, IEEE Antennas and Wireless Propagation Letters, 12: 1492–1495, (2013).
• [6] Wen, H., Weng, Y., Qi, Z., Li, F. and Fan, J., “A Multiband Dual-Polarized Omnidirectional Antenna for 2G/3G/LTE Applications”, in IEEE Antennas and Wireless Propagation Letters, 17(2): 180-183, (2018).
• [7] Alieldin, A., Huang, Y., Boyes, S. J., Stanley, M., Joseph, S. D., Hua, Q. and Lei, D., “A triple-band dual-polarized indoor base station antenna for 2G, 3G, 4G and sub-6 GHz 5G applications”, in IEEE Access, 6: 49209-49216, (2018).
• [8] Cui, G., Zhou, S. G., Gong, S. X., and Liu, Y., “A compact dual-polarized antenna for base station application”, Progress in Electromagnetics Research Letters, 59: 7-13, (2016).
• [9] Zhou, S., Tan, P. and Chio, T., “Low-profile, wideband dual-polarized antenna with high isolation and low cross polarization”, IEEE Antennas and Wireless Propagation Letters, 11: 1032-1035, (2012).
• [10] He, Y., Yue, Y., and Shen, Z., “A novel broadband dual polarized antenna element for LTE700 MHz/GSM850 MHz/GSM900 MHz applications”, IEEE Access, 4: 4321-4326, (2016).
• [11] Kaboli, M., Mirtaheri, S. A. and Abrishamian, M. S., “High-isolation X-polar antenna” IEEE Antennas and Wireless Propagation Letters, 9: 401-404, (2010).
• [12] Kaboli, M., Abrishamian, M. S., Mirtaheri, S. A. and Aboutorab, S. M., “High-isolation XX-polar antenna”, IEEE Transactions on Antennas and Propagation, 60(9): 4046-4055, (2012).
• [13] White, C. R., Rebeiz, G. M., “A differential dual-polarized cavity-backed microstrip patch antenna with independent frequency tuning”, IEEE Transactions on Antennas and Propagation, 58 (11): 3490-3498, (2010).
• [14] Lau, K. L., Luk, K. M., and Lin, D., “A wide-band dual-polarization patch antenna with directional coupler”, IEEE Antennas and Wireless Propagation Letters, 1: 186-189, (2002).
• [15] Ciydem, M., “Wideband dual polarized antenna”, Journal of the Faculty of Engineering and Architecture of Gazi University, 29(4): 817-821, (2014).
• [16] Ciydem, M., “Isolation enhancement in wideband dual‐polarised suspended plate antenna with modified T‐type probes”, Electronics Letters, 50(5): 338-339, (2014).
• [17] Ciydem, M., Koc, S., “High isolation dual‐polarized broadband antenna for base stations”, Microwave and Optical Technology Letters, 57(3): 603-607, (2015).
• [18] Ciydem, M., Miran, E. A., “Dual-polarization wideband sub-6 GHz suspended patch antenna for 5G base station”, IEEE Antennas and Wireless Propagation Letters, 19(7): 1142-1146, (2020).
• [19] Abbosh, M., “Ultra wideband vertical microstrip-microstrip transition”, IET Microwaves, Antennas and Propagation, 1(5): 968–972, (2007).
• [20] Ciydem, M., “A Low-Profile Dual-Polarized Antenna with High Isolation and High Front-to-Back Ratio for 5G Base Stations”, The Applied Computational Electromagnetics Society Journal (ACES), 36(9): 1229-1236, (2021).
• [21] Miran, E. A., Ciydem, M., “Dual-polarized elliptic-H slot-coupled patch antenna for 5G applications”, Turkish Journal of Electrical Engineering and Computer Sciences, 30(4): 1204-1218, (2022).