Surface acoustic wave device comprising piezoelectric substrate having zinc oxide layer on .alpha.-alumina layer
US4236095A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1979 |
| Grant date | Nov 25, 1980 |
| Priority date | — |
| Expiry date | Apr 17, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H3/08
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A surface acoustic wave device comprising a piezoelectric substrate which comprises an .alpha.-alumina layer as a base region and a zinc oxide layer as a surface region formed on the .alpha.-alumina layer. Preferably the two layers are each made of a single crystal, and the thickness of the zinc oxide layer and an angle between a crystallographic axis of the zinc oxide single crystal and the direction of wave propagation are determined so as to fall within optimum ranges, respectively. This device features an increased phase velocity and an augmented value for the electromechanical coupling coefficient and accordingly is of use at very-high to ultra-high frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.