Rotation-Driven Phase Modulation in a Mechanical Gear-Matrix Metasurface for Beam Splitting, Wide-Angle Scanning, Polarization Conversion

초록

Simultaneous polarization conversion, beam scanning, and beam splitting are essential for advanced wireless systems requiring adaptive, multifunctional wavefront control. We present a mechanically reconfigurable metasurface driven by a gear matrix network, enabling wide-angle circular polarization (CP) beam scanning through linear-to-circular polarization (LP-to-CP) conversion, as well as the generation of right- and left-handed CP (RHCP and LHCP) components via coordinated rotation of unit cells (UCs). Rotation-driven phase modulation provides a scalable and power-efficient approach to radiofrequency beam manipulation. Unlike electronically tunable systems based on positive-intrinsic-negative diodes or transistors—often limited by cost, complexity, and scalability—the proposed system relies entirely on mechanical phase modulation for dynamic beam control. Each UC integrates a rotary dual X–Y polarization-to-CP frequency selective surface and a central rotation gear connected to a rack-and-gear array, enabling row-wise tuning of the output phase. The phase of the transmitted wave varies according to the rotation angle (α) applied to the X–Y polarization components. By precisely controlling the phase gradient through mechanical rotation, the metasurface achieves beam scanning over a wide angular range of ± 70°, while simultaneously generating RHCP and LHCP components. Experimental results show excellent agreement with full-wave simulations, validating the effectiveness of the gear matrix architecture.

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