Enhancing Low-Frequency Acceleration Resolution of Resonant Accelerometers by Manipulating the Bias Voltage Noise

The phase noise in resonant accelerometer (RXL) determines the resolution. The bias voltage noise applied on the sensing resonator is typically suppressed to prevent the detrimental effect of the noise conversion in the oscillating loop. However, this paper proposes that manipulating the cut-off frequency and amplitude of the bias voltage noise spectrum can enhance the resolution of RXL in low-frequency range, because the 1/f
³
phase noise of resonator and 1/f
³
noise of bias voltage noise may cancel each other. The simulation and experimental results demonstrated that the resolution of prototype RXL at 0.01Hz can be improved over 2X to $\sim 50ug/\sqrt {Hz} $.