Methods for Nonlinearities Reduction in Micromechanical Beams Resonators

In this paper, two methods for reducing the nonlinearities in microelectromechanical systems flexural beams resonators have been demonstrated with established theoretical models and validated experimental results. The first method improves the conventional method of mutual cancellation between nonlinearities, in which the electrical nonlinearity has been decoupled utilizing the tuning capacitors inside a comb-drive DETF resonator to be used to controllably cancel the mechanical nonlinearity, which makes the nonlinearity reduction tunable and, meanwhile, alleviates the discontinuity of frequency spectrum, thus improving the frequency stability. The second method based on a fundamental view to redesign the DETF resonator into a doublefree semicircular beam resonator that can be operated at an elastic mode to eliminate the axial extension existing in the stretch mode of DETF and minimize the A-f effect. The proposed methods can effectively reduce the nonlinearity to achieve resonators with a wide linear regime, high signal-to-noise ratio, and good capability of power handling.