TWO-DIMENSIONAL COUPLED ELECTROSTATIC-MECHANICAL MODEL FOR RF MEMS SWITCHES

摘要

Two-dimensional (2-D) coupled electrostatic-mechanical model of RF MEMS switches has been developed, in which the effect of residual stress due to the fabrication process and axial force resulting from the beam stretching have been taken into account. The electrostatic model is based on the application of the finite difference (FD) technique to quasi-static solution of a 2-D plane cut of the MEMS switch structure. The electrostatic model calculates the induced electrostatic force on the membrane due to the applied dc bias voltage. From the resulting electrostatic potential, the force distribution, the switch capacitance, and the beam deformation have been calculated. The computed pull down voltage for different structures agrees well with published data. The developed simulation program combines the electrostatic and mechanical analyses together and gives accurate results in short running time.