A system includes a sensor device, a circuit driving he sensor device at a drive frequency, a receiver, and a low pass filter. The sensor device is configured to change its electrical characteristics in response to external stimuli. The sensor device generates a modulated signal proportional to the external stimuli. The receiver is configured to receive the modulated signal and further configured to demodulate the modulated signal to generate a demodulated signal. The demodulation signal has a guard band. The receiver consumes power responsive to receiving the modulated signal. The low pass filter is configured to receive the demodulated signal and further configured to generate a sensor output.