Surface acoustic wave device
US6037699A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 9, 1998 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Jan 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02559
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention provides a surface acoustic wave device which has a thin film formed on a surface of a substrate adapted to excite longitudinal wave-type surface acoustic waves, longitudinal wave-type quasi surface acoustic waves or longitudinal wave-type surface skimming bulk waves to thereby give an increased electromechanical coupling coefficient and at the same time minimize the temperature coefficient of delay time. For example, in a surface acoustic wave device having an aluminum thin film formed on a surface of a lithium tantalate substrate, the direction of propagation of longitudinal wave-type quasi surface acoustic waves is (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles and within a range equivalent thereto, and the product of wave number of longitudinal wave-type quasi surface acoustic waves and the thickness of the thin film is at least 1.0, preferably in the range of 1.3 to 2.0. The device provided exhibits higher performance than in the paior art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.