Optimal Terminating Impadances for Maximizing the Gains of a Four-Coil WPT Link

In this paper, a Wireless Power Transfer (WPT) link consisting of four magnetically coupled resonators (a transmitting and a receiving resonator coupled through two relay elements) is analyzed. Standard gain definitions are used for describing the performance of the link and the analytical expressions of the terminating impedances providing the optimal operating conditions are derived.