CMUT with mechanically coupled plate actuators -Linearized electrostatic modeling

Abstract

This paper derives an analytical model of the electrostatic transduction of a capacitive micromachined ultrasonic transducer (CMUT) with mechanically coupled plate actuators. The mass of the coupling geometry significantly affects the dynamic deflection shape of the plate actuators. As the electrostatic transduction of a CMUT depends on the distance between both electrodes of these capacitive systems, the static and dynamic deflection shapes are taken into account for the small signal electrostatic behavior. The analysis of the electrostatic lumped elements, varying with the bias voltage, reveals a dependence on the deflection shape. A comparison with finite element simulations shows good agreement with the analytical model.