# Design of Tunable Broadband Graphene-Based Metasurface with Amplitude-Phase Modulation
## 6 Conclusions  
In this work, a multifunctional metasurface with reflective amplitude-phase modulation is designed based on graphene. Graphene is commonly used in the terahertz band, and this work applies it to the W-band. The metasurface is composed of a \(5\times 5\) array consisting of only 25 units. By varying the Fermi level to encode the reflective amplitude and phase of the graphene metasurface, the metasurface has the capacity to execute beam steering and multi-beam switching concurrently. The graphene-based metasurface achieves beam reconstruction function over an exceptionally wideband from 75 to 91.5 GHz and 99.3 to 115 GHz. Compared to traditional phased array antennas, the graphene metasurface offers numerous advantages such as wide working bandwidth, simple structure, and lightweight design, making it an ideal candidate for vehicle-borne radar, satellite communication, and 6G wireless communication.  
**Author Contributions:** All authors have significantly contributed to the research presented in this manuscript; [PERSON] presented the main idea and wrote the manuscript; [PERSON] and [PERSON] edited the manuscript; [PERSON] and [PERSON] reviewed and revised the manuscript. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the Guangxi Major Projects of Science and Technology under Grant AA21077006; in part by Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing under Grant GXKL06190115 and Guangxi Key Laboratory of Information Materials under Grant 221033-K.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data sharing is not applicable to this article.  
**Conflicts of Interest:** The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **[30]** & **[16]** & **[31]** & **[32]** & **[33]** & **This Work** \\ \hline \begin{tabular}{c} Operating \\ Frequency Band \\ \end{tabular} & 2.57–2.64 GHz & 6-14 GHz & \begin{tabular}{c} 0.56–0.74 THz, \\ 0.75–0.98 THz and \\ 0.99–1.08 THz \\ \end{tabular} & 1.38–1.56 THz & 1–1.4 THz & \begin{tabular}{c} 75–91.5 GHz, \\ 99.3–115 GHz \\ \end{tabular} \\ \hline \begin{tabular}{c} Regulating \\ components or \\ materials \\ \end{tabular} & \begin{tabular}{c} High dielectric \\ fluid \\ \end{tabular} & Graphene & Graphene & Graphene and VO\({}_{2}\) & Graphene \\ \hline \begin{tabular}{c} Coding method \\ \end{tabular} & Phase & Phase & Amplitude and \\ \hline \begin{tabular}{c} Beam steering angle \\ \end{tabular} & Theta = \(\pm 20^{\circ}\) & Theta = \(\pm 53.7^{\circ}\) & Not mentioned & \begin{tabular}{c} Six metasurfaces are \\ arranged around \\ the antenna to \\ achieve phi = 360\({}^{\circ}\) \\ beam steering \\ \end{tabular} & From theta = 0° to \\ \begin{tabular}{c} Beam steering angle \\ \end{tabular} & Theta = \(\pm 20^{\circ}\) & Theta = \(\pm 53.7^{\circ}\) & Not mentioned & \begin{tabular}{c} Six metasurfaces are \\ arranged around \\ the antenna to \\ achieve phi = 360\({}^{\circ}\) \\ beam steering \\ \end{tabular} & From theta = 0° to \\ \begin{tabular}{c} Beam steering \\ \end{tabular} & \
\begin{tabular}{c} From theta = \(\pm 60^{\circ}\) in \\ the antenna to \\ achieve phi = 68.37\({}^{\circ}\) \\ beam steering \\ \end{tabular} &
\begin{tabular}{c} Theta = \(\pm 25^{\circ}\) in \\ the