A resonant matching circuit (310) for matching a resonant frequency of a wireless power transfer system to a frequency of a power signal comprises a switch (311) connected in parallel with a resonant element (302) of the wireless power transfer N system; and a controller (312) connected to the switch (311) and configured to detect a zero-voltage level crossing of a signal flowing through the resonant element (302) and to close the switch (311) for a predefined amount of time upon detection of the zero-voltage level crossing, wherein closing the switch (311) for the predefined amount of time adds any one of an inductive value and a capacitive value to the resonant frequency of a wireless power transfer system.