PIEZOELECTRIC SENSOR HAVING NON-PERFECTLY CLAMPED EDGES

The subject of this paper is an analytical model describing the behavi our of a telephone piezoelectric sensor. Modelling takes into account the clamping conditions of the diaphragm in its plastic case and also the acoustic elements of the transducer (cavities and holes). The edge conditions of the diaphragm are characterized solely by a global para meter allowing continuous variation from clamped to free edges. Then t he theoretical resonant frequencies, the electrical impedance and the sensitivity of the transducer can be determined as a function of the e dge clamping conditions of the diaphragm. They depend upon both the el asticity of the plastic case and the variation of fabrication of the t ransducer elements.