Simultaneous Phase- and Frequency-Tunable Hybrid Coupler - Zheng, Shao Yong (IEEE transactions on industrial electronics (1982), 2017)
Keywords: Branch line coupler; Capacitors; Couplers; Frequency control; frequency tunable; hybrid coupler; Mathematical model; Performance enhancement; Phase shift; Phase shifters; phase tunable; Ports (Computers); varactor loaded; Varactors