Example embodiments are directed to a device comprising an antenna circuit that receives a radio frequency (RF) signal and that converts the RF signal into an electrical signal, a sensing circuit that senses the electrical signal and that outputs an output signal based on the sensed electrical signal, at least one processing circuit that generates at least one control signal based on the output signal, and a switching circuit that couples the antenna circuit to either the sensing circuit to enter a standby mode of the device or to the at least one processing circuit to exit the standby mode and enter an active mode of the device based on the at least one control signal.