Transversely excited film bulk acoustic resonator with recessed interdigital transducer fingers
US10985726B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 14, 2020 |
| Grant date | Apr 20, 2021 |
| Priority date | — |
| Expiry date | Aug 14, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/54
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having front and back surfaces, the back surface attached to a surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The IDT is configured to excite a primary acoustic mode in the diaphragm in response to a radio frequency signal applied to the IDT. At least one finger of the IDT is disposed in a groove in the diaphragm. A depth of the groove is equal to a thickness of the at least one finger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.