Yu Run, Liu Dong, Cai Xinhang, Zhou Qi, Wang Mao, Jin Lin, Sun Jiandong, Li Xinxing, Qin Hua
School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, 230026, China.
Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, 215123, China.
Adv Mater. 2025 Jul 14:e2507534. doi: 10.1002/adma.202507534.
Effective wavefront control in the terahertz (THz) regime is essential for achieving high-directionality beamforming, spatial multiplexing, and real-time wireless communication. However, low-loss, precise, and rapid THz phase modulation remains fundamentally constrained by material limitations and inherent device-level trade-offs. A programmable THz metasurface (GaNMS) is presented, employing a gallium nitride Schottky barrier diode with a high-mobility 2D electron gas, specifically designed to overcome these limitations by leveraging its low insertion loss, fast response, and continuously tunable junction capacitance. A 32 × 25-element array is designed and fabricated. Each unit cell functions as a direct THz phase shifter, dynamically tuning the junction capacitance to enable continuous phase modulation from 0° to 210° at 0.32 THz, with a 1.8° average phase error, modulation speed exceeding 200 MHz, and ≈5 dB average insertion loss. To mitigate array-level nonuniformities, a differential evolution-based optimization algorithm is introduced, enabling robust ±45° beam scanning in both analog and digital modes, with main lobe gains of 18.5 and 16 dBi, respectively. An integrated GaNMS-based sensing and communication system is also demonstrated, validating its potential in next-generation THz applications. The proposed GaNMS bridges device-level phase tunability and system-level functionality, enabling practical THz technologies.
在太赫兹（THz）波段实现有效的波前控制对于实现高定向波束形成、空间复用和实时无线通信至关重要。然而，低损耗、精确且快速的太赫兹相位调制仍然受到材料限制和固有器件级权衡的根本制约。本文提出了一种可编程太赫兹超表面（GaNMS），它采用具有高迁移率二维电子气的氮化镓肖特基势垒二极管，专门设计用于通过利用其低插入损耗、快速响应和连续可调结电容来克服这些限制。设计并制作了一个32×25元阵列。每个单元电池用作直接太赫兹移相器，动态调节结电容，在0.32太赫兹频率下实现从0°到210°的连续相位调制，平均相位误差为1.8°，调制速度超过200兆赫兹，平均插入损耗约为5分贝。为了减轻阵列级的不均匀性，引入了一种基于差分进化的优化算法，在模拟和数字模式下实现了±45°的稳健波束扫描，主瓣增益分别为18.5和16 dBi。还展示了一个基于GaNMS的集成传感与通信系统，验证了其在下一代太赫兹应用中的潜力。所提出的GaNMS弥合了器件级相位可调性和系统级功能之间的差距，实现了实用的太赫兹技术。
