Elastic wave device, high-frequency front-end circuit, and communication apparatus
US11228300B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2018 |
| Grant date | Jan 18, 2022 |
| Priority date | — |
| Expiry date | Nov 18, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/14541
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An elastic wave device includes a piezoelectric layer, an IDT electrode on the piezoelectric layer, a high-acoustic-velocity member, a low-acoustic-velocity film between the high-acoustic-velocity member and the piezoelectric layer. The piezoelectric layer is made of lithium tantalate, the IDT electrode includes metal layers including an Al metal layer and a metal layer having a higher density than Al. Expression 1 is satisfied: 301.74667−10.83029×TLT−3.52155×TELE+0.10788×TLT2+0.01003×TELE2+0.03989×TLT×TELE≥0 expression 1, where λ represents a wavelength defined by an electrode finger pitch of the IDT electrode, TLT (%) represents a normalized film thickness of the piezoelectric layer to the wavelength λ, and TELE (%) represents a normalized film thickness of the IDT electrode in terms of Al to the wavelength λ.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.