An analytical design methodology for microelectromechanical (MEM) filters

The design of coupling spring for a microelectromechanical (MEM) filter is driven by the requirements of bandwidth. A novel design aspect of the coupling spring design is presented which follows mechanical–electrical–mechanical domains in order. A designed second order MEM bandpass filter consists hereby of two laterally/vertically driven resonance structures, which are coupled by a mechanical spring. For these structures, an equivalent electrical representation can be obtained and in this paper, both the series and parallel electrical equivalent circuits are analyzed. The transfer function and the correlation between the bandwidth and the coupling spring for these filter equivalents are derived. T d a s ©