Finite element and equivalent circuit modeling of capacitive micromachined ultrasonic transducer (CMUT) /

In this thesis, a precise finite element model (FEM) of capacitive micromachined ultrasonic transducer is developed. Trough the results of the FEM, an equivalent circuit model of a transducer is built which enables high efficient design of transceiver front-end integrated circuit with a better known transducer behavior. Consequently, more realistic simulation results of the overall system can be obtained. The FEM model is created in the ANSYS environment and all simulations are done in 3D. The model can also be used to determine the proper parameters (e.g. radius, thickness, gap height) for the target of operation without fabrication. The equivalent circuit that is constructed over the Mason model is improved for immersion applications with modeling the radiation impedance with an RLC circuit and defining an effective transformer ratio value. Modeling results match actual measurements with a very good accuracy