In accordance with some embodiments of the present disclosure, a circuit comprises a balun configured to receive a radio frequency (RF) signal at a first input port and a second input port of an input coil. The balun is further configured to output the RF signal at an output coil communicatively coupled to the input coil. The circuit also comprises a supply voltage selector circuit coupled to the input coil and configured to adjust a bias voltage at the input coil according to a power level of the RF signal received at the input coil.