18‐2: A Novel Design for Reconfigurable Intelligent Surfaces (RIS) with Thin Liquid Crystal Layer for Wireless Communications

This paper proposes a proof‐of‐concept design for RIS made with liquid crystals (LC) and Corning glass for wireless communication applications. The proposed RIS concept consists of the specially designed copper‐coated glass substrates and liquid crystal materials that were filled in between two glass substrates. The LC layer exists between the upper and lower Corning glass sheets, and it is 20 μm thick. Although the 20 μm cell‐gap is very thin compared to the operating frequency (it is more than 100 μm in previous research), more than the 180° phase difference was achieved by applying 10 V in the designed frequency band. Our proposed concept can improve wireless communication coverage by reflecting incident electromagnetic waves in the desired direction to secure a propagation path by simply changing the alignment of LC molecules under different driving voltages. Also, conventional LCD manufacturing technology can significantly reduce costs and support larger sized capabilities, compared to incumbent semiconductor‐based electronics and printed circuit board (PCB) processing.