Systems for tuning a wireless power transfer system are provided, which may include any number of features. In one embodiment, a wireless power transfer system can include a transmit controller connected to the transmitter resonator and configured to measure an impedance on the transmitter resonator. The transmit controller can be configured to determine a load resistance of the receiver resonator and a coupling coefficient between the transmitter and receiver resonators based on the measured impedance on the transmitter resonator. The transmit controller can be further configured to adjust a power transmission parameter of the transmitter resonator based on the determined load resistance and the coupling coefficient to achieve a controlled voltage at a load of the receiver. Methods of use are also provided.
