Due to manufacturing uncertainties and due to geometric constraints on the moving structure, the drive mode of MEMS gyroscopes may exhibit high intrinsic nonlinearity [1], [5]. The type of the drive mode nonlinearity is mainly quadratic in amplitude [5], [6]. Thus, a cubic nonlinearity term can account for the geometric nonlinearities of the structure [4], [5], [6], [7]. Here, we present a method to model the drive mode nonlinearity to first order in frequency by using static analysis in the finite element domain. We construct the free parameter in the Duffing nonlinearity term using the results of the static analysis tool. Finally, we verify the 1D Duffing oscillator model with full transient FE simulations of a MEMS gyroscope test structure.
