Intrinsically Switchable Ferroelectric Contour Mode Resonators

Abstract

This paper presents the design and measurement results of intrinsically switchable interdigitated contour mode resonators based on barium titanate (BTO) thin films. The resonators have lithographically defined interdigitated electrodes that determine their resonance frequencies. The BTO thin film exhibits electrostriction, which allows the resonances to be switched on and off. The highest frequency device exhibits series and parallel resonance frequencies of 1.67 and 1.68 GHz and quality factors of 178 and 152, respectively, with the application of a 10-V dc bias. Resonances are turned off by removing the dc bias. This is the first demonstration of an intrinsically switchable interdigitated ferroelectric contour mode resonator. Index Terms-Ferroelectric devices, interdigital transducers, microelectromechanical systems (MEMS).

From Microwave Acoustic Filters to Millimeter-Wave Operation and New Applications

“…BAW resonators based on ferroelectric BST exhibit several interesting features, allowing potential simplification of RF frontends. Due to BST's strong electrostriction properties, BST resonators can be switched on and off with the application of a DC bias voltage [91], [92], [93], [94], [95], [96], [97], [98], [99], [100], [101], [102], [103], [104], [105]. A photograph of an intrinsically switchable BST FBAR is shown in Fig.…”

“…An example of TFE interdigitated contour mode resonators, which excites under the application of an RF signal and DC bias to the interdigitated electrodes is shown in Fig. 24 [103].…”