Design to improve the capacitive contact quality in piezoelectric actuation

RF MEMS switches with piezoelectric actuation permits us to obtain a reliable switch relative to electrostatic actuated switches since the dielectric charging is reduced and fast respond. The problem here is the deformation induced by the actuation is transmitted to the capacitor plate and by consequences: we lose in the value of capacitance in the down state due to the air gap. A study of the air pp effect on the capadtance value in the down state is done in the first part, showing the importance of flatness in capacitor plate designs. The design that is described in this paper, deals with the point of the application of the force in order to flatten the contact between the electrodes forming the capacitor. An analytical model describing the deformation of the switch was developed.