Li, J., F. Wang, G. Wen, Y. Huang, and W. Zhu. 2021. “Planar Metamaterial for Matched Waveguide Termination”. Applied Computational Electromagnetics Society Journal (ACES) 28 (12):1236-43. https://journals.riverpublishers.com/index.php/ACES/article/view/11257.