HIGH-FIDELITY MEMS SWITCH MODEL
Y.H.Park,Y. Miyazaki and K.C.Park
University of Colorado at Boulder, US
Keywords: MEMS switch, contact model, high fidelity simulation
MEMS switches have used in a wide variety of microwave applications because of low loss and small measurable signal distortion since the switching action is accomplished by mechanical contact. While various microswitches are currently being developed, the dynamic behavior is not well understood, especially the contact mechanism between switch-substrate electrode. Once the switch starts to contact, it bounces many times before making a permanent contact. Most conventional switch simulation models often utilize an artificial penalty function or linear spring to model the on-off type contact mechanism which is not a physics based model. In this work, to account for the area contact motion, a localized Lagrange multiplier method is utilized in nonlinear governing dynamic equation, i.e., this simulation model includes finite element model of electrode foundation as well as nonlinear membrane switch. The numerical model of clamped-ended membrane-type switch is verified by comparing with the analytical solution of membrane electrostatic actuator, for which both have pull-down time of 2.4 micro-sec. The simulation result shows that 1.2 micro-sec extra time (30 % of pull-down time) is required to get a permanent contact, because of the bounce motion of the switch.
NSTI Nanotech 2003 Conference Technical Program Abstract