Intrinsically switchable ferroelectric BAW resonators and filters

In this paper, intrinsically switchable radio frequency (RF) resonators and bandpass filters using ferroelectric thin film technology are presented. Ferroelectrics materials exhibit electrostriction and dc electric field induced piezoelectricity. This paper discusses the design and fabrication of intrinsically switchable film bulk acoustic resonators (FBARs), FBAR filters, and contour mode resonators by employing the dc electric field induced piezoelectricity of the ferroelectric Ba_xSr_(1-x)TiO₃. Such resonators and filters have the ability to decrease the complexity, power consumption, and cost of frequency agile radios while improving their performance and reliability.