Parametrically Exicited Mems-based Filters

In this paper we describe the dynamics of MEMS oscillators that can be used as frequency filters. The unique feature of these devices is that they use parametric resonance, as opposed to the usual linear resonance, for frequency selection. However, their response in the parametric resonance zone has some undesirable features from the standpoint of filter performance, most notably that their bandwidth depends on the amplitude of the input and the nonlinear nature of the response. Here we provide a brief background on filters, a MEMS oscillator that overcomes some of the deficiencies, and we offer a description of how one might utilize a pair of these MEMS oscillators to build a band-pass filter with nearly ideal stopband rejection. These designs are made possible by the fact that MEMS devices are highly tunable, which allows one to build in system features to achieve desired performance.