The Cochrane Database of Systematic Reviews

A thin film resonator comprising a piezoelectric material and having a controllable or tunable resonant frequency. The resonator is formed on a substrate having a cavity formed therein below the piezoelectric film material. A bending electrode is disposed within the cavity and the application of a voltage between the bending electrode and one of the resonator electrodes, creates an electric field that causes the substrate region to bend. These stresses caused: by the bending are transferred to the thin film resonator, subjecting the piezoelectric film to stresses and thereby changing the resonant properties of the thin film resonator.