FEM based modeling of tunable BAW resonators with Ba0.8Sr0.2TiO3

In this paper, a finite element method and multiphysics based 3D modeling of tunable ferroelectric thin film resonator taking the advantages of electrostrictive and piezoelectric effects of Ba
0.8
Sr
0.2
TiO
3
thin film. DC electrical field dependency of the dielectric permittivity and elasticity coefficients can control the resonances in the thin film. The resonator has a series resonant frequency of 4.33 GHz and parallel resonance at 4.43 GHz with applied DC voltage of 2 V. The electromechanical coupling coefficient is measured at 5.4% and increased to be 8% with the biasing voltage at 8V.