Feed-through cancellation of a MEMS filter using the difference method and analysis of the induced notch
使用差分方法消除微机电滤波器的穿通以及对由此引入的陷波现象的分析

This paper presents and analyzes a notch observed in MEMS (micro electric mechanical system) filter characterization using the difference method. The difference method takes advantage of the cancellation of parasitic feed-through, which could potentially obscure the relatively small motional signal and lead to failure in characterization of the MEMS components. In this paper, typical clamped-clamped beam MEMS filters are fabricated and characterized with the difference method. Using the difference method a better performance is obtained but a notch is induced as a potential problem. Analysis is performed and reveals the mismatch of the two differential excitation signals in measurement circuit contributes to the notch. The relevant circuit design rule is also proposed to avoid the notch in the difference method.