A second harmonic based resonance characterization method for MEMS electrostatic resonators

This paper presents a novel read-out approach both for eliminating parasitic feedthrough current and for enhancing the quality-factor (Q) of the resonating system at the same time. A new resonance characterization method based on sensing second harmonic component of the resonators was developed. Utilizing this method, the feedthrough current was eliminated and the signal-to-background ratio was increased from 0.9 dB to 35.5 dB. Furthermore, the Q of the resonating system was improved by 65% experimentally. It was shown that this method is suitable for eliminating both capacitive and resistive feedthrough current without using complex MEMS designs and interface electronics.