Zi-Yu Pang, Xiao-Yu Ma, Ge Zhao, Jia-Jun Liang, Guan-Long Huang, Luyu Zhao, and Chow-Yen-Desmond Sim. “A 3D Printed Filtering Waveguide With Simple Metamaterial Construction”. Applied Computational Electromagnetics Society Journal (ACES), vol. 35, no. 5, May 2020, pp. 539-44, https://journals.riverpublishers.com/index.php/ACES/article/view/7955.