Surface acoustic wave device, surface acoustic wave filter and antenna duplexer using the same, and electronic equipment using the same
US8035460B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2007 |
| Grant date | Oct 11, 2011 |
| Priority date | — |
| Expiry date | May 1, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/42
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A surface acoustic wave device includes a substrate including lithium niobate; a IDT being provided on an upper surface of the substrate and including a plurality of electrode fingers; and a protective film covering the IDT and having an uneven shape on an upper surface thereof. When a pitch width of one pitch of the IDT is p, a width of one of the electrode fingers is p1, a width between the electrode fingers is p2, and a thickness of the IDT is h, following relations are satisfied, p1+p2=p, and h/(2×p)≧4.5%. With this configuration, an appropriate reflection characteristic is realized, and the surface acoustic wave device having excellent temperature coefficient of frequency and electrical characteristic can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.