Design and Analysis of a 1-Bit Reflective Metasurface for Reconfigurable Intelligent Surface Applications in the Ka-Band

In this work, a 1-bit reflective metasurface for reconfigurable intelligent surfaces (RISs) in the Ka-band is proposed. The design uses linear polarization and a PIN diode for phase properties to achieve two distinct phase states, providing a wide bandwidth and precise phase control. The PIN diode switches between these two states. The reflecting element is uniquely configured with the bias circuit and a PIN diode in the center of two triangle patches to improve antenna efficiency. This element is used to enhance the performance of a 5λ × 5λ reconfigurable reflect array antenna. The simulation results show that the proposed design has a strong signal focus, good surface area utilization, and adaptable performance with a peak gain of 19.5 dBi, an aperture efficiency of 18%, and effective beam-scanning capabilities.