Complex elastic coefficient and mechanical losses for piezoelectric resonators under transversal and thickness modes

ABSTRACTThe performance of piezoelectric transducers depends upon a set of physical parameters. Among them, losses are one of the most important. Mechanical losses in piezoelectric devices are studied using complex numbers in the elastic coefficients of the models. Usually, numerical methods are employed to obtain the loss parameters through the minimization of an error function. We insert mechanical losses dependent on frequency in Mason's model to evaluate how this dependency affects the electrical impedance curve. The results show that a better curve fitting is achieved when the mechanical loss is a first order function of frequency.