The effect of charge redistribution on limiting the kt2.Q product of piezoelectrically transduced resonators

In this paper, we introduce a new loss mechanism that can significantly limit the quality factor (Q) of piezoelectrically transduced resonators. We show that the electromagnetic energy dissipated in the anharmonic process of free charge redistribution on metallic electrodes placed on commonly used piezoelectric materials sets a limit for the resonator Q that is frequency independent and is much smaller than the Akheiser Q limit at frequencies less than 1 GHz. To validate this theory, the Q limit is formulated for extensional bulk acoustic modes with in-plane polarization and compared with published measured data, showing reasonable agreement.