Gravity-Driven Dual-Axis Feed Mechanism with Gap Waveguide for Passive Beam Stabilization in E-Band Backhaul Systems

Journal article, 2026

To support high data rates and low-latency E-band wireless backhaul for future 6G and dense network deployments, this paper presents an ultra-high-gain (UHG), dual-polarized parabolic reflector antenna system with automatic beam steering by employing a two-dimensional (2D) movable feed based on gap waveguide technology to stabilize the beam direction when the reflector experiences sway due to strong winds or vibrations. UHG parabolic reflectors offer excellent gain. However, their extremely narrow beamwidth makes them highly sensitive to misalignment of the beam caused by wind and vibrations. To address this issue, this paper proposes a mechanically movable feed architecture that enables automatic dynamic beam alignment within ±2.5° while avoiding the need for a costly high-frequency motor-servo–based beam-steering system. Mechanical analysis and measurements confirm smooth, low-friction motion of the feed on a 2D platform, while electromagnetic evaluations verify stable dual-polarization performance, demonstrating the feasibility and reliability of the proposed system for E-band backhaul applications. A gravity-driven passive beam-stabilization mechanism is introduced. By leveraging mass displacement and spring coupling, the feed position automatically adjusts in real-time response to mast tilt, thereby maintaining real-time beam alignment. Theoretical analysis and prototype validation demonstrate that the system provides a compact, energy-free beam-alignment solution with high mechanical robustness, making it particularly well suited for communication and sensing applications on dynamic platforms.