Zhou, J. ., M. . Chen, R. . Zhong, and S. . Liu. “Analysis of TM and TE Modes in Eccentric Coaxial Lines Based on Bipolar Coordinate System”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 30, no. 12, Aug. 2021, pp. 1313-21, https://journals.riverpublishers.com/index.php/ACES/article/view/10301.