摘要
This study presents a generic feedthrough (FT) cancellation technique for MEMS resonators based on magnetically induced suppression through interconnect magnetic effects. A Thin-film Piezoelectric-on-Silicon (TPoS) resonator was employed to demonstrate this technique by terminating both input and output (I/O) ports. The method leverages electromagnetic-induced currents to counteract capacitive feedthrough signals from parasitic components that are typically found in MEMS devices. The technique consistently enhances the stopband rejection (SBR) performance of the tested device by approximately 20 dB across a broad frequency range while maintaining resonant amplitude levels. Notably, it remains effective in liquid environments, reducing FT to levels comparable to those in ambient conditions that apply the same technique, significantly improving the SBR from about 3 dB (due to increased FT and liquid damping) to around 25 dB (with only damping effect present). This improvement makes the resonance in liquid more distinguishable. An oscillator utilizing this technique, demonstrated via a commercial lock-in amplifier, achieved a mass resolution of 4.36 pg in liquid. The proposed technique is versatile, applicable to any device with parallel current-carrying electrode routing between I/O ports.