Saw multiplexer with SWA filters having different bandwidths due to dielectric layer between IDT and piezoelectric layer adjusting acoupling factor
US12308822B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 9, 2020 |
| Grant date | May 20, 2025 |
| Priority date | — |
| Expiry date | Nov 18, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/725
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The SAW filter chip comprises a plurality of SAW filters (1, 2), wherein at least one of the several electric filters is a first-type electric filter (1) comprising at least one first-type SAW-resonator (10). The first-type SAW-resonator comprises a piezoelectric layer (11), an intermediate layer (12) on the piezoelectric layer (11) and an interdigital electrode structure (13) on the intermediate layer (12). The interdigital electrode structure is separated from the piezoelectric layer by the intermediate layer. The intermediate layer is made of a dielectric, non-piezoelectric material and adjusts the electromechanical coupling factor and the bandwidth of the respective filter. The plurality of SAW filters form an LTE multiplexer, wherein the thickness of the intermediate layer is chosen to adjust the required bandwidth to the desired bands. The intermediate layer may be absent for larger required bandwidths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.