Gyrator-type equivalent circuit for piezoelectric transducers

The authors consider piezoelectric transducers operating in the thickness vibration mode, and with the electric field parallel to the motion. It is shown that if the development of the equivalent circuit for the transducers is based on the dielectric constant for constant stress, the static capacitance is defined for free-running transducer conditions. This capacitance can be measured more easily than the capacitance for clamped conditions. In this case, the electromechanical conversion is represented by a gyrator