Design, Fabrication, and Validation of an Integrated Antenna for Autonomous Train Control System: Supporting LTE-R, 5G, GPS, and V2X

Autonomous Train Control Systems (ATCS) require highly reliable and low-latency wireless communication to support real-time decision-making and train coordination. This paper presents the design, fabrication, and validation of an integrated multi-band antenna system optimized for ATCS applications. The proposed antenna supports LTE-R, 5G sub-6 GHz, private 5G (e-Um), V2X, and GPS bands within a compact structure, enabling simultaneous connectivity to diverse wireless systems. The base-station antenna module utilizes miniaturized ultra-wideband monopole elements to achieve $4 \times 4$ MIMO operation with omnidirectional coverage, while the V2X module employs a $2 \times 8$ directional patch array to ensure high-gain train-to-train communication. A commercial GPS module with circular polarization is also integrated for precise positioning and synchronization. The antenna system was fabricated and tested through full-wave simulation, lab measurements, and full-scale field trials. Measured results demonstrate stable operation across all frequency bands, high isolation, and low envelope correlation coefficients, validating the system’s suitability for deployment in next-generation autonomous railway networks.