Transversely-excited film bulk acoustic filter using pitch to establish frequency separation between resonators
US12034428B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2020 |
| Grant date | Jul 9, 2024 |
| Priority date | — |
| Expiry date | Nov 14, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2003/0442
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Acoustic filters are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces and a thickness ts, the back surface attached to the surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms that span respective cavities in the substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern comprising a plurality of interdigital transducers (IDTs) of a plurality of acoustic resonators, interleaved fingers of each IDT of the plurality of IDTs disposed on a respective diaphragm of the plurality of diaphragms. The interleaved fingers of all of the plurality of IDTs are substantially aluminum with a common thickness tm, where 0.12 ts≤tm≤0.32 ts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.