Abstract
This paper proposes a novel antenna structure that simultaneously satisfies high gain, dual-polarization, and fan-beam radiation pattern characteristics for Private 5G base stations in next-generation railway communications. In Private 5G railway communications, a balance of high gain, dual-polarization, and fan-beam is crucial. High gain and fan-beam pattern maximize coverage along the track, while dual-polarization provides link robustness for high-speed mobility. The proposed antenna element achieves a high gain of 12.8 dBi and stable radiation performance despite its relatively compact size by employing a radiation mechanism based on a higher-order mode patch antenna and a sidelobe suppression technique utilizing central and side slots. Furthermore, by rotating the antenna by 45\(^\circ\) and configuring it in a slant dual-polarization structure, it provides robustness against polarization variations that frequently occur in practical communication environments. A 6 \(\times\) 1 array antenna constructed based on the proposed antenna element forms a stable fan-beam radiation pattern with suppressed grating lobes even at wide array spacing of 1.27\(\lambda _0\), providing a horizontal half-power beamwidth (HPBW) of 6\(^\circ\), a vertical HPBW of 38\(^\circ\), and a peak gain of 18.6 dBi. The 6-way power divider designed for dual-polarization array feeding ensures excellent uniform power distribution with an insertion loss deviation within ± 0.32 dB and an insertion phase deviation within ± 2.8\(^\circ\). Both the proposed antenna element and the array antenna achieve sufficient bandwidth coverage for the Private 5G band, demonstrating performance suitable for application in practical base station environments. Moreover, a figure-of-merit comparison defined based on peak gain, fractional bandwidth, and antenna size confirms that the proposed antenna achieves the most balanced performance compared to previously reported high gain dual-polarized antennas. These results indicate that the proposed antenna can provide high reliability for next-generation Private 5G railway base stations and offer significant advantages in terms of coverage, interference mitigation, and link robustness in practical railway operating environments.
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Data availability
The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. The photographs used in Figs. 7, 8, and 10 of our manuscript were taken by B. K. Ahn and are original images.
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J.-G. L. conducted design and simulations, J.-G. L. and Y. H. conducted experiments, J.-G. L. and B. K. A. analyzed the data and wrote the manuscript. All authors reviewed the manuscript.
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Lee, JG., Han, Y. & Ahn, B.K. High gain and slant dual-polarized antenna for private 5G railway base stations. Sci Rep (2026). https://doi.org/10.1038/s41598-026-45487-0
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DOI: https://doi.org/10.1038/s41598-026-45487-0
