Zayed, Ayman S. Al-, Zuhair. M. Hejazi, and Ashraf S. Mohra. 2022. “A Microstrip Directional Coupler With Tight Coupling and Relatively Wideband Using Defected Ground Structure”. Applied Computational Electromagnetics Society Journal (ACES) 25 (10):877-87. https://journals.riverpublishers.com/index.php/ACES/article/view/15801.