Filter using transversely-excited film bulk acoustic resonators with multiple frequency setting layers
US10992284B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 2020 |
| Grant date | Apr 27, 2021 |
| Priority date | — |
| Expiry date | Jul 8, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/877
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Acoustic filters and methods are disclosed. A single-crystal piezoelectric is attached to a substrate, portions of the piezoelectric plate forming one or more diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators, interleaved fingers of each of the plurality of IDTs disposed on a respective diaphragm of the one or more diaphragms. A first frequency setting dielectric layer having a first thickness is disposed over the fingers of the IDTs of a first subset of the plurality of resonators. A second frequency setting dielectric layer having a second thickness greater than the first thickness is disposed over the fingers of the IDTs of a second subset of the plurality of resonators, wherein the first subset and the second subset are not identical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.