Haruo Kawakami, Masao Tanioka, and Ryoji Wakabayashi. “Circularly Polarized Log Periodic Dipole Antennas”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 35, no. 11, Nov. 2020, pp. 1312-3, https://journals.riverpublishers.com/index.php/ACES/article/view/7509.