High frequency microelectromechanical IF filters

High frequency, IC-compatible microelectromechanical IF filters with integrated filter Q´s in the hundreds have been demonstrated using a polysilicon surface micromachining technology. These filters are comprised of two micromechanical resonators coupled by soft mechanical springs. The center frequency of a given filter is determined by the resonance frequency of the constituent resonators, while the bandwidth is determined by the coupling spring dimensions and its location between the resonators. By taking advantage of low velocity spring coupling locations, high filter Q´s are attainable despite the use of low mass micro-scale resonator elements. Filter center frequencies from 3-10 MHz with Q´s from 10-400 are demonstrated using low velocity designs.