A 2-bit Programmable Metasurface Antenna With Simple Structure, High-Level Integration, and Wide-Angle Multipolarization Beam Scanning

In this article, a novel programmable metasurface (PM) is proposed, characterized by simple structure, high-level integration, multiple polarization modes (including dual-linear and dual-circular polarizations), wide scanning angle, and low scanning loss. Equivalent circuit theory is employed, making it convenient to design a 2-bit unit cell with simplified structure. The proposed unit cell has only two substrates, five radio frequency (RF) electronic components, and five metalized vias, which, to the best of our knowledge, represent the fewest components reported for 2-bit dual-polarized unit cells. A $12\times 12$ scale metasurface is designed, fabricated, and measured. The direct current (dc) control circuit is ingeniously integrated behind the metasurface, resulting in a total thickness of just 5.34 mm for both the metasurface and the control circuit. This highly integrated control scheme eliminates the need for at least one substrate, two metal layers, and hundreds of external wires, significantly reducing both the complexity and cost of the PM. The measurements show good agreement with the simulations. The proposed metasurface can steer beams with multiple polarization modes within a range of ±60°, requiring only a single linearly polarized feed source. The antenna achieves a maximum aperture efficiency (AE) of 35.35% in linearly polarized modes and 32.02% in circularly polarized modes. The proposed metasurface has potential in various fields, including satellite communication, radar detection, wireless power transmission, and reconfigurable intelligent surface (RIS)-assisted communication.