1-Bit Active Phase-Reconfigurable Unit Cell Ris for Next Generation Wireless Communication

Reconfigurable Intelligent Surfaces (RIS) have emerged as a transformative solution for next-generation wireless networks, offering a low-power and cost-efficient means of controlling electromagnetic wave propagation. Through the integration of tunable elements within engineered metasurfaces, RIS can dynamically adjust the phase, amplitude, or polarization of incoming signals, enabling flexible and programmable wireless environments suitable for $\mathbf{5 G}, \mathbf{6 G}$, and beyond. In this work, an active 1-bit RIS unit cell is designed and analyzed using full-wave simulation, featuring a PIN diode as the rapid switching element. The active configuration supports binary phase modulation, providing two discrete reflection states determined by the diode bias condition. The unit cell is further optimized to yield an approximately 180° phase shift between the ON and OFF states, with a tolerance of $\pm 20^{\circ}$ at $\mathbf{4. 6 ~ G H z}$, ensuring reliable and consistent operation at the intended frequency. Simulation results verify that the use of the PIN diode enables fast and efficient reconfigurability without compromising compactness or practical implementability. These outcomes advance ongoing RIS research and establish a solid platform for future hardware fabrication, prototyping, and experimental validation.