A bidirectional circuit for actuation and read-out of resonating sensors

In this paper we have demonstrated a novel approach for actuation and read-out of resonating sensors. In this approach, instead of reading the amplitude of the resonating beam in resonance, we use the frequency of the beam as a measure of the sensors response. By using a bidirectional amplifier a pulse is sent to a resonating sensor in one direction and the frequency response of the sensor is measured using the opposite direction of the amplifier. This approach results in more compact and more power conservative systems. This approach mimics the way radars operate where a pulse is sent out and the reflection is measured. The circuit is very compact with low component spread and consumes an average power of 22μW and a maximum power of 100μW when actuating the sensor.