Filters using transversly-excited film bulk acoustic resonators with frequency-setting dielectric layers
US12170516B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2023 |
| Grant date | Dec 17, 2024 |
| Priority date | — |
| Expiry date | Sep 28, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/877
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Filter devices are disclosed. A filter device includes a piezoelectric plate comprising a supported portion, a first diaphragm, and a second diaphragm. The supported portion is attached to a substrate and the first and second diaphragms spans respective cavities in the substrate. A first interdigital transducer (IDT) has interleaved fingers on the first diaphragm. A second interdigital transducer (IDT) has interleaved fingers on the second diaphragm. A first dielectric layer is between the interleaved fingers of the first IDT, and a second dielectric layer is between the interleaved fingers of the second IDT. A thickness of the first dielectric layer is greater than a thickness of the second dielectric layer. The piezoelectric plate and the first and second IDTs are configured such that radio frequency signals applied to first and second IDTs excite primary shear acoustic modes in the respective diaphragms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.