B.Ravi Shankar, J.Sailaja, V. Ravi Sekhara Reddy, G.V.Sai Divya, B.Bhanu Prakash,. 2020. “Design of Harmonic Suppressed Branch Line Coupler With Size Reduction Using Three Shunt Open Stub Unit”. International Journal of Advanced Science and Technology 29 (3), 3651 -59. http://sersc.org/journals/index.php/IJAST/article/view/5045.