In an embodiment, a circuit includes a resonant portion, a plurality of switches, a first impedance, an amplifier, and a demodulator. The resonant portion includes a single RF coil and is configured for transmission/reception at about the same frequency. The switches include first, second, and third switches. The first switch includes an input in communication with a power source and an output in communication with ground. The second switch includes an input between the power source and the first switch and an output in communication with a resonant portion input. The third switch includes an input in communication with a resonant portion output and an output in communication with ground. The first impedance is between the resonant portion output and the third switch input. The amplifier includes an input between the first impedance and the third switch input. The demodulator includes an input in communication with the amplifier output.