Mechanical quality factor of multilayer piezoelectric ceramic transducers

It has long been known that the mechanical quality factor at resonance for multilayer piezoelectric transducers decreases as the number of ceramic layers is increased. We investigated this phenomenon using multilayer transducers, which are driven in a longitudinal mode of the piezoelectric transverse-effect. In this report, we express equivalent circuits for the transducers with resistance for electrode layers, We concluded that the mechanical quality factor at resonance for the transducers decreases because the ratio of resistance for electrode layers to the total equivalent resistance increases with the number of ceramic layers.