Simulating Nonlinearity in MEMS Resonators by a Charge Controlled Capacitor

In this paper, a novel circuit formulation allowing co-simulation of nonlinearity in MEMS resonators and interface circuits in a generic circuit simulation platform is reported for the first time. A charge controlled capacitor is used to model the nonlinear restoring force in the mechanical resonator. The concept has been applied to the case of a longitudinal beam resonator, illustrating the effect of feedthrough in the limit of nonlinear behavior characterized by features such as spring softening and hysteresis.