Nonlinear Effects of SiO₂ Layers in Bulk Acoustic Wave Resonators

Abstract

This paper presents the development of a comprehensive distributed circuit model to account for the existing nonlinear effects in bulk acoustic wave (BAW) resonators. The comprehensiveness of the model and its distributed implementation allow for the inclusion of the nonlinear effects occurring in any layer of the BAW configuration, not only the piezoelectric layer. The model has been applied to evaluate the nonlinear contribution of the piezoelectric layer and silicon dioxide (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) layer in the Bragg reflector. The nonlinear manifestations are a function of the frequency of the driving fundamental tones. Accurate measurements of state-of-the-art resonators validate the model proposed and confirm the contribution of the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer in the overall nonlinear performance.