Characterization and modeling of a contour mode mechanical resonator using piezoresistive sensing with quasi-differential inputs

In this paper we present, for the first time, a piezoresistive bulk mode microelectromechanical systems (MEMS) resonator that employs a passive differential input to suppress parasitic feedthrough. This novel compact approach lies in contrast to conventional methods using a dummy resonator. Our approach makes use of additional non-active (passive) wire bonds to match the parasitics of the device under test. We show here that a 37.75 dB decrease in feedthrough level is achieved while the measured resonant peak height increases correspondingly from 0.22 to 9.32 dB as a result of applying the novel passive differential scheme. Furthermore, a semi-analytical model is developed to predict the piezoresistive frequency response of the device. From the close fit between the presented model and the measured data, we show that our model is able to predict the response of our device. (paper)