Xue Bai, Jia-wei Zhang, Lei-jun Xu, and Bu-hui Zhao. “A Broadband CPW Fractal Antenna for RF Energy Harvesting”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 33, no. 05, July 2021, pp. 482-7, https://journals.riverpublishers.com/index.php/ACES/article/view/9147.