Cavity-less film bulk acoustic resonator (FBAR) devices
US7332985B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 2004 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | Jan 11, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/605
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The film bulk acoustic resonator (FBAR) device comprises a substrate, an acoustic Bragg reflector over the substrate, a piezoelectric element over the acoustic Bragg reflector, and a remote-side electrode over the piezoelectric element. The acoustic Bragg reflector comprises a metal Bragg layer juxtaposed with a plastic Bragg layer. The large ratio between the acoustic impedances of the plastic material of the plastic Bragg layer and the metal of the metal Bragg layer provides sufficient acoustic isolation between the FBAR and the substrate for the frequency response of the FBAR device to exhibit minor, if any, spurious artifacts arising from undesirable acoustic coupling between the FBAR and the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.