Compact, gain-enhanced 5G mmWave antenna with metallic ground-backed reflector for high-speed railway communication systems

Abstract

This research presents a compact, high-gain millimeter-wave antenna tailored for reliable 5 G communication in high-speed railway environments. The proposed antenna supports dual-band operation at 28 GHz (n257/n258) and 38 GHz (n260), enabling robust Vehicle-to-Infrastructure (V2I) links required for next-generation railway systems. The radiator occupies only 12 mm × 8 mm on a Rogers 6010LM substrate (εᵣ = 10.2, h = 0.64 mm). A Metallic Ground-Backing (MGB) reflector, positioned 9 mm behind the patch—λ/4 at 28 GHz—enhances forward radiation, suppresses back-lobes, and ensures highly directional coverage along railway tracks. The antenna achieves measured peak gains of 7.96 dBi at 28 GHz and 8.20 dBi at 38 GHz, with excellent impedance matching and stable radiation patterns under mobility scenarios. Its unique combination of compact footprint, reflector-aided gain enhancement, and stable dual-band performance under dynamic conditions distinguishes it from conventional millimeter-wave solutions, making it a strong candidate for 5G-based high-speed railway communication modules and arrays.

Keywords

Millimeter-wave antenna / Metallic ground backing reflector / Gain enhanced / 28/38 GHz / Compact / High-speed railway

CRediT authorship contribution statement

Ahmed J.A. Al-Gburi: Writing – review & editing, Validation, Supervision, Project administration, Investigation. Dunya Zeki Mohammed: Writing – original draft, Software, Methodology, Data curation, Conceptualization.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgment

The authors would like to thank Universiti Teknikal Malaysia Melaka (UTeM) and the Ministry of Higher Education Malaysia (MOHE) for supplying the necessary materials for fabrication—such as the Rogers 6010LM substrate. We are also grateful to Universiti Teknologi Malaysia (UTM) for granting access to its mmWave measurement facilities. Finally, we acknowledge Gilgamesh University for its support with design and technical research writing.

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