A Dual‐Programmable Metasurface with Duplex Beam Steering for Full‐Space Terahertz Communications

Abstract Programmable metasurfaces capable of full‐space terahertz (THz) beam steering offer immense potential for new‐paradigm THz applications. Nonetheless, achieving dual programmability for integrated transmission and reflection (T‐R) modes poses significant challenges in THz bands. Here, a dual‐programmable THz metasurface is proposed based on polarization allocation with 2D‐electron‐gas (2DEG) regulations. It breaks through the limitations in resonant tunability, enabling a single resonator to mingle two distinct 1‐bit phase‐shifting channels. These channels are allocated to the T‐R modes through four on/off states, which can independently define the operation modes and phase states. A prototype is fabricated and tested, demonstrating full‐space beam steering in the D‐band with a duplex bandwidth of 24 GHz. In addition, the transmission mode can support amplitude modulation at a megahertz‐level rate while maintaining the beam steering capability. With the assistance of this metasurface, real‐time THz beam‐tracking communications are implemented across transmission and reflection zones, delivering stable and lag‐free 1080p/30fps video streaming to a moving receiver. This work paves a path to future THz wireless networks with versatile and multi‐node coordination.