“…To isolate the HF generators from the reflected power, at JET [5] and ASDEX Upgrade [6], a system using 3 dB hybrid couplers was successfully used. Many tokamak teams have studied and implemented matching systems that can be used in real time, including the internal conjugate-T system of impedance matching at WEST [7] and for ITER-like antenna at JET [5], the external conjugate-T impdance-matching system at JET [8,9], the liquid dielectric stubs at EAST [10] and LHD [11], and the TOKAMAKS ferrite tuners at Alcator C-Mod [12,13], EAST [14], and KSTAR [15].…”