Improved tunable performance of high Q-factor BaxSr1−xTiO3 film bulk acoustic wave resonators

Improved tunable performance of high Q-factor Ba
_x
Sr
_1-x
TiO
₃
film bulk acoustic wave resonators (FBARs), achieved by varying Ba concentration, is demonstrated. The Ba
_0.5
Sr
_0.5
TiO
₃
FBARs reveal tunability of series resonance frequency up to 2.4%, electromechanical coupling coefficient up to 7.5% and rather high figure of merit, Qf≈1300 GHz. Correlations between the measured electroacoustic parameters are analyzed using the theory of dc bias induced piezoelectric effect in paraelectric phase ferroelectrics.