Large-Signal Performance and Modeling of Intrinsically Switchable Ferroelectric FBARs

Abstract

This paper presents the large-signal performance of intrinsically switchable ferroelectric thin-film bulk acoustic resonators (FBARs), as well as their modeling procedure. There has been a growing interest in ferroelectric FBARs due to their electric-field-dependent permittivity and electric-field-induced piezoelectricity. Ferroelectric barium-strontium-titanate (Ba <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> Sr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(1-</sub> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> )TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) FBARs are intrinsically switchable, namely, they have resonances that switch on with the application of a dc-bias voltage. In this paper, the large-signal performance and nonlinear behavior of ferroelectric BST FBARs are investigated. Measurement results show that the device nonlinearity can be reduced by applying higher dc-bias voltages. Moreover, a large-signal model that accurately describes the dc-bias voltage, as well as RF power-dependent performance of BST FBARs is developed. Large-signal simulation results obtained from this model at different bias voltages and RF power levels show good agreement with the measurement results.