An algorithm for automatic model-order reduction of nonlinear MEMS devices

In this paper, we apply the Arnoldi method to generate accurate reduced-order models for coupled energy domain nonlinear microelectromechanical devices. Besides the traditional application of Arnoldi method to generate reduced-order models for linear system, we propose a new algorithm by combining Arnoldi method and Taylor series expansion for doing model-order reduction on quadratic or even higher order nonlinear systems. A well-known nonlinear MEMS device, electrostatic actuated fixed-fixed beam device with squeeze-film damping effect, is studied. Simulation results demonstrate that the reduced nonlinear model has a much better accuracy to capture the original device behavior than the simple linearization method. The reduced MEMS device model can be easily connected to a circuit simulator for efficient system-level simulations.