A Guided‐Wave Inspired Reconfigurable Intelligent Surface With Independent Continuous Control of Reflection Amplitude and Phase for Wireless Communications

ABSTRACT In this article, a guided‐wave‐inspired reconfigurable intelligent surface (RIS) with independent continuous amplitude and phase control ability is proposed. The designed RIS unit cell mainly consists of a top square patch, a middle metal ground, and a bottom reconfigurable attenuator‐phase shifter cascade structure. By applying different bias voltages, the proposed RIS achieves a continuous amplitude modulation of 0.2–0.78 and a continuous phase modulation of 410° at 4.9 GHz. As a validation, a RIS array consisting of 12 × 12 elements is fabricated and measured, generating dual beams with independent beam pointing and required power intensity allocation. Correspondingly, a RIS‐assisted wireless communication system is constructed, and the performance of the proposed RIS is verified through image information transmission. In addition, a sub‐bias network that can be flexibly extended according to the scale of the RIS array is designed to solve the problem of the increasing complexity of bias network arrangement caused by independent modulation of amplitude and phase. The proposed RIS has great application potential in RIS‐assisted wireless communication systems, especially in scenarios where power intensities of the beams are allocated based on the data transmission rate requirements of different devices.