Dual Linearly Polarized Wide Beamwidth Antenna for Private-5G Supportive MIMO Applications

This paper presents a dual linearly polarized planar antenna element optimized for private 5G applications in the 4.6–4.9 GHz frequency band, targeting Korea’s 4.7 GHz allocation. Wide beamwidth antenna elements are increasingly critical in private 5G (P5G) networks to simplify base station architecture and enable efficient MIMO implementation without sectorization, making them a cost-effective solution. Nevertheless, simultaneous improvement in both beamwidth and bandwidth for dual-polarized planar antennas has rarely been demonstrated, due to technical challenges associated with antenna volume, fabrication complexity, and cost constraints. To achieve wide angular coverage while addressing these design challenges, a dielectric grid layer (DGL) is integrated into the dual-polarization antenna design. The DGL refracts the radiated energy outward through angular phase transformation, effectively enhancing the half-power beamwidth (HPBW). The proposed antenna achieves an HPBW exceeding 131°, enabling single-element sector coverage well-suited for compact and high-performance deployments. The design offers high polarization purity, with cross-polarization discrimination greater than 25.2 dB and port-to-port isolation exceeding 28.6 dB, facilitating reliable dual-polarized MIMO operation. The peak realized gain surpasses 2.5 dBi across the operational band. Simulation results are validated through measurements, showing good agreement in radiation patterns, beamwidth, and polarization characteristics. With its broad angular coverage, dual linear polarization, and high isolation, the proposed antenna provides a cost-effective, compact, and fabrication-friendly solution for next-generation P5G-MIMO platforms, ensuring practical and efficient deployment.