volume | PIER Journals

Abstract

We present an eight-page in-depth study of a single-layer broadband reflectarray antenna operating over the 8 GHz to 12 GHz X-band. The array employs a dual-ring hex-slit unit cell and a physics-informed deep-learning (DL) surrogate model that reduces geometry optimisation time by ×120 compared with brute-force sweeps. The 30 cm × 30 cm prototype comprises 273 passive elements, delivers a 530° reflection-phase span, 27 dB peak gain, 56% aperture efficiency and 34.6 dB cross-polar discrimination. A residual network trained on 5000 HFSS datapoints predicts reflection phase with 0.9° MAE, whereas its inverse sibling outputs element radii in 10 ms. CST full-wave simulations and a preliminary S-parameter measurement corroborate the synthesis accuracy to within 0.25 dB. Comprehensive parametric, angular-stability and computational analyses provide guidance for extending DL-assisted reflectarrays to higher frequencies and reconfigurable architectures.

1. Huang, John and José A. Encinar, Reflectarray Antennas, John Wiley & Sons, 2007.
doi:10.1002/9780470178775

2. Pozar, D. M., "Bandwidth of reflectarrays," Electronics Letters, Vol. 39, No. 21, 1490-1491, 2003.
doi:10.1049/el:20030990 Google Scholar

3. Li, Long, Qiang Chen, Qiaowei Yuan, Kunio Sawaya, Tamami Maruyama, Tatsuo Furuno, and Shinji Uebayashi, "Frequency selective reflectarray using crossed-dipole elements with square loops for wireless communication applications," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 1, 89-99, 2011.
doi:10.1109/tap.2010.2090455 Google Scholar

4. Peng, Jun-Jie and Shi-Wei Qu, "Ultra-wideband reflectarray with multi-resonance elements," 2017 International Applied Computational Electromagnetics Society Symposium (ACES), 1-2, Suzhou, China, 2017.

5. Targonski, S. D., D. M. Pozar, and H. D. Syrigos, "Analysis and design of millimeter wave microstrip reflectarrays," IEEE Antennas and Propagation Society International Symposium. 1995 Digest, Vol. 1, 578-581, Newport Beach, CA, USA, 1995.
doi:10.1109/APS.1995.530085

6. Bodur, Hande, Sibel Ünaldı, Sibel Çimen, and Gonca Çakır, "Broadband single‐layer reflectarray antenna for X‐band applications," IET Microwaves, Antennas & Propagation, Vol. 12, No. 10, 1609-1612, 2018.
doi:10.1049/iet-map.2017.0270 Google Scholar

7. Qin, Pei-Yuan, Y. Jay Guo, and Andrew R. Weily, "Broadband reflectarray antenna using subwavelength elements based on double square meander-line rings," IEEE Transactions on Antennas and Propagation, Vol. 64, No. 1, 378-383, 2016.
doi:10.1109/tap.2015.2502978 Google Scholar

8. Wang, S., L. Li, S. Gong, and Y. Yang, "A dual-polarisation broadband reflectarray using modified cross-loop elements," IEEE Antennas and Wireless Propagation Letters, Vol. 13, 1292-1295, 2014. Google Scholar

9. Li, H., B.-Z. Wang, and W. Shao, "Novel broadband reflectarray antenna with compound-cross-loop elements for millimeter-wave application," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 10, 1333-1340, 2007.
doi:10.1163/156939307783239528 Google Scholar

10. Encinar, J. A., "Design of two-layer printed reflectarrays using patches of variable size," IEEE Transactions on Antennas and Propagation, Vol. 49, No. 10, 1403-1410, 2001.
doi:10.1109/8.954929 Google Scholar

11. Deng, Y., Deep learning for the inverse design of metasurface-based energy materials. YouTube video, Duke University Energy Initiative (Energy Data Analytics Ph.D. Student Fellows Lightning Talk), 5 min 19 s., Available: https://www.youtube.com/watch?v=aeH9p9wkdoA, 2021.

12. Lu, Darui, Yang Deng, Jordan M. Malof, and Willie J. Padilla, "Learning electromagnetic metamaterial physics with ChatGPT," IEEE Access, Vol. 13, 51513-51526, 2025.
doi:10.1109/access.2025.3552418 Google Scholar

13. Veluchamy, Lingasamy, M. Gulam Nabi Alsath, and Krishnasamy T. Selvan, "Design and evaluation of a wideband reflectarray antenna using cross dipole with double-ring elements," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 29, No. 9, e21865, 2019.
doi:10.1002/mmce.21865 Google Scholar

14. Shaker, Jafar, Mohammad Reza Chaharmir, and Jonathan Ethier, Reflectarray Antennas: Analysis, Design, Fabrication, and Measurement, Artech House, 2013.

15. Wang, Quan, Zhenhai Shao, PengKai Li, Long Li, and YuJian Cheng, "A dual polarization, broadband, millimeter-wave reflectarray using modified cross loop element," Microwave and Optical Technology Letters, Vol. 56, No. 2, 287-293, 2014.
doi:10.1002/mop.28065 Google Scholar

16. Chaharmir, M. R., J. Shaker, M. Cuhaci, and A. Ittipiboon, "Broadband reflectarray antenna with double cross loops," Electronics Letters, Vol. 42, No. 2, 65-66, 2006.
doi:10.1049/el:20063299 Google Scholar

17. Hamzavi-Zarghani, Zahra and Zahra Atlasbaf, "A new broadband single-layer dual-band reflectarray antenna in X-and Ku-bands," IEEE Antennas and Wireless Propagation Letters, Vol. 14, 602-605, 2014.
doi:10.1109/lawp.2014.2374351 Google Scholar

18. Costanzo, Sandra, Francesca Venneri, Antonio Borgia, and Giuseppe Di Massa, "Dual-band dual-linear polarization reflectarray for mmWaves/5G applications," IEEE Access, Vol. 8, 78183-78192, 2020.
doi:10.1109/access.2020.2989581 Google Scholar

19. Koziel, Slawomir, Mehmet Ali Belen, Alper Çalişkan, and Peyman Mahouti, "Rapid design of 3D reflectarray antennas by inverse surrogate modeling and regularization," IEEE Access, Vol. 11, 24175-24184, 2023.
doi:10.1109/ACCESS.2023.3254204 Google Scholar

20. Derafshi, Iman, Nader Komjani, and Mohammad Mohammadirad, "A single-layer broadband reflectarray antenna by using quasi-spiral phase delay line," IEEE Antennas and Wireless Propagation Letters, Vol. 14, 84-87, 2015.
doi:10.1109/lawp.2014.2355496 Google Scholar

Dr. Mohammadjavad Zakeri

Dr. Sajjad Sadeghi