Dynamics of Micromechanical Capacitive Shunt Switches

Abstract -- An analytical approach based on unidimensional equations has been settled up for studying the dynamics of RF MEMS switches. The model has been developed until now especially for shunt capacitive configurations, to predict the capacitance change and actuation times during the actuation and de-actuation mechanisms, and it has been implemented by means of a MATHCAD program. Successively, two- and three-dimensional models based on a commercial software package, namely COMSOL Multiphysics, using equations about energy conservation and boundary conditions, has been used to validate the analytical one and to clearly identify the limits and advantages of a fully analytical formulation. The dynamical response of a capacitive shunt switch has been considered, but the approach is generally valid for resistive series as well as for capacitive shunt devices, because they refer to a double clamped beam, independently of the electrical configuration.