Zayed, Ayman S. Al-, Zuhair. M. Hejazi, and Ashraf S. Mohra. “A Microstrip Directional Coupler With Tight Coupling and Relatively Wideband Using Defected Ground Structure”. Applied Computational Electromagnetics Society Journal (ACES) 25, no. 10 (June 17, 2022): 877–887. Accessed May 13, 2026. https://journals.riverpublishers.com/index.php/ACES/article/view/15801.