Lin, Yi-Fang, Yu-Chang Kao, Hua-Ming Chen, and Shan-Cheng Pan. 2022. “Bidirectional Radiated Circularly Polarized Annular-Ring Slot Antenna for Portable RFID Reader”. Applied Computational Electromagnetics Society Journal (ACES) 25 (3):182-89. https://journals.riverpublishers.com/index.php/ACES/article/view/15603.