volume | PIER Journals

Abstract

The role and applications of millimeter wave (mmWave) Reconfigurable Intelligent Surfaces (RIS) have been rapidly increasing by extending the signal coverage with energy and spectrum efficiency. However, the current RIS designs pose challenges like size and angular insensitivity with efficient beamforming functionalities. In this article, we propose a compact and angularly stable RIS unitcell with incident and polarization angle insensitivity in reflection mode. The footprint of the FR4 substrate is 10x10x1.6 mm³ in size. The unitcell structure consists of circular patch inner cuts as a top layer with a full ground. An AlGaAs pin diode is inserted in the middle of the top layer to get the beamforming. The switchable states provide peak resonance at 32.5 GHz (Bandwidth-444 MHz) and 33.6 GHz (Bandwidth-498 MHz) frequencies. Significant gain values of 11.5 and 13.7 dBi are achieved at the operating frequencies. The designed unitcell provides angular stability up to 90˚ oblique incidences and polarization angles. The AlGaAs pin diode is controlled by applying suitable bias levels using Arduino Uno. The numerical simulation results and experimental validation are performed with incident and polarization angles, which are suitable for adapting to the challenges in mmWave applications.

1. Liu, Yuanwei, Xiao Liu, Xidong Mu, Tianwei Hou, Jiaqi Xu, Marco Di Renzo, and Naofal Al-Dhahir, "Reconfigurable intelligent surfaces: principles and opportunities," IEEE Communications Surveys and Tutorials, Vol. 23, No. 3, 1546-1577, 2021.
doi:10.1109/COMST.2021.3077737

2. Pan, Cunhua, Hong Ren, Kezhi Wang, Jonas Florentin Kolb, Maged Elkashlan, Ming Chen, Marco Di Renzo, Yang Hao, Jiangzhou Wang, A. Lee Swindlehurst, Xiaohu You, and Lajos Hanzo, "Reconfigurable intelligent surfaces for 6G systems: principles, applications, and research directions," IEEE Communications Magazine, Vol. 59, No. 6, 14-20, Jun. 2021.
doi:10.1109/MCOM.001.2001076

3. Rappaport, Theodore S., Yunchou Xing, Jr. MacCartney, Andreas F. Molisch, Evangelos Mellios, and Jianhua Zhang, "Overview of millimeter wave communications for fifth-generation (5G) wireless networks-with a focus on propagation models," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 12, 6213-6230, Dec. 2017.
doi:10.1109/TAP.2017.2734243

4. Rana, Biswarup, Sung-Sil Cho, and Ic-Pyo Hong, "Review paper on hardware of reconfigurable intelligent surfaces," IEEE Access, Vol. 11, 29614-29634, 2023.
doi:10.1109/ACCESS.2023.3261547

5. Saifullah, Yasir, Yejun He, Amir Boag, Guo-Min Yang, and Feng Xu, "Recent progress in reconfigurable and intelligent metasurfaces: A comprehensive review of tuning mechanisms, hardware designs, and applications," Advanced Science, Vol. 9, No. 33, 1-35, Nov. 2022.
doi:10.1002/advs.202203747

6. Zhang, Lei and Tie Jun Cui, "Angle-insensitive 2-bit programmable coding metasurface with wide incident angles," Proceedings of The 2019 IEEE Asia-pacific Microwave Conference (APMC), 932-934, Singapore, Dec. 2019.
doi:10.1109/apmc46564.2019.9038764

7. Liang, Jing Cheng, Qiang Cheng, Yuan Gao, Cong Xiao, Shang Gao, Lei Zhang, Shi Jin, and Tie Jun Cui, "An angle-insensitive 3-bit reconfigurable intelligent surface," IEEE Transactions on Antennas and Propagation, Vol. 70, No. 10, 8798-8808, Oct. 2022.
doi:10.1109/TAP.2021.3130108

8. Wang, Ruiqi, Yiming Yang, Behrooz Makki, and Atif Shamim, "A Wideband Reconfigurable Intelligent Surface for 5G Millimeter-Wave Applications," arXiv preprint arXiv:2304.11572, 2023.

9. Shekhawat, A. S., B. G. Kashyap, P. C. Theofanopoulos, A. P. S. Sengar, and G. C. Trichopoulos, "A Compact Unit-cell Design for mmWave Reconfigurable Intelligent Surfaces," 2022 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM), 84-85, Boulder, CO, USA, 2022.

10. Dai, Linglong, Bichai Wang, Min Wang, Xue Yang, Jingbo Tan, Shuangkaisheng Bi, Shenheng Xu, Fan Yang, Zhi Chen, Marco Di Renzo, Chan-Byoung Chae, and Lajos Hanzo, "Reconfigurable intelligent surface-based wireless communications: antenna design, prototyping, and experimental results," IEEE Access, Vol. 8, 45913-45923, 2020.
doi:10.1109/ACCESS.2020.2977772

11. Gros, Jean-Baptiste, Vladislav Popov, Mikhail A. Odit, Vladimir Lenets, and Geoffroy Lerosey, "A Reconfigurable Intelligent Surface at mmWave Based on a Binary Phase Tunable Metasurface," IEEE Open Journal of The Communications Society, Vol. 2, 1055-1064, 2021.
doi:10.1109/OJCOMS.2021.3076271

12. Saifullah, Yasir, Fuheng Zhang, Guo-Min Yang, and Feng Xu, "3-bit programmable reflective metasurface," 2018 12th International Symposium on Antennas, Propagation and Electromagnetic Theory (ISAPE), 1-2, Hangzhou, Dec. 2018.

13. Trichopoulos, Georgios C., Panagiotis Theofanopoulos, Bharath Kashyap, Aditya Shekhawat, Anuj Modi, Tawfik Osman, Sanjay Kumar, Anand Sengar, Arkajyoti Chang, and Ahmed Alkhateeb, "Design and evaluation of reconfigurable intelligent surfaces in real-world environment," IEEE Open Journal of The Communications Society, Vol. 3, 462-474, 2022.
doi:10.1109/OJCOMS.2022.3158310

14. Hu, Jingzhi, Hongliang Zhang, Boya Di, Lianlin Li, Kaigui Bian, Lingyang Song, Yonghui Li, Zhu Han, and H. Vincent Poor, "Reconfigurable Intelligent Surface Based RF Sensing: Design, Optimization, and Implementation," IEEE Journal on Selected Areas in Communications, Vol. 38, No. 11, 2700-2716, Nov. 2020.
doi:10.1109/JSAC.2020.3007041

15. Vamseekrishna, Allam, Boddapati Taraka Phani Madhav, Tirunagari Anilkumar, and Lakkam Siva Shanker Reddy, "An IoT Controlled Octahedron Frequency Reconfigurable Multiband Antenna for Microwave Sensing Applications," IEEE Sensors Letters, Vol. 3, No. 10, 1-4, Oct. 2019.
doi:10.1109/LSENS.2019.2943772

Dr. Badisa Anil Babu

Dr. Pulletikurthi Ram Kalyan

Dr. Varanasi Venkata Lakshmi

Dr. Rana Reharika

Dr. Nakka Varun Raj