Large dynamic range time domain measurement of Q-factor in MEMS

The experimental identification of the quality factor in MEMS is a challenging task regarding signal processing and interpretation. Using logarithmic amplification some benefits regarding the signal processing and the reliability of the results can be achieved. This paper reports on two logarithmic amplification methods which allow an easy to use resource efficient measurement of the quality factor in MEMS. The logarithmic behavior enables the measurement of movement amplitude dependent quality factor in one measurement window. A rectifying amplifier and a full logarithmic amplifier are described and measurement examples are shown.