Patent US4189516A successfully refreshed from Google Patents.
US4189516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epitaxial crystalline aluminium nitride
Assignee: National Research Development Corp UK
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Filing: 1978-07-17
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Granted: 1980-02-19
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Expires: 1998-07-17
Abstract
Abstract Material suitable for a surface acoustic wave device comprises an epitaxial film of aluminum nitride on the surface of a substrate of single crystal aluminum oxide, said surface having the crystallographic orientation 1100.
Inventors
- 👤 Peter M. Dryburgh
- 👤 Raymond R. Halstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:10
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5053; C04B41/5062; C04B41/5063; C04B41/80; C04B41/81; C04B41/85; C04B41/87; G; G10; G10K; G10K11/00; G10K11/36; Y; Y10; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
33 words
Material suitable for a surface acoustic wave device comprising an epitaxial film of aluminum nitride on the surface of a substrate of single crystal aluminum oxide, said surface having the crystallographic orientation 1100.
Claim 2
Dependent Claim
33 words
Material suitable for a surface acoustic wave device comprising an epitaxial film of aluminum nitride on the surface of a substrate of single crystal aluminum oxide, said surface having the crystallographic orientation 1100.
Claim 3
Dependent Claim
32 words
A surface acoustic wave device comprising material as in claim 1 and interdigital transducers on said epitaxial film suitable for the launching and reception of surface acoustic waves in said epitaxial film.
Claim 4
Dependent Claim
13 words
Material as claimed in claim 1 and wherein said substrate is of alumina.
Claim 5
Dependent Claim
13 words
Material as claimed in claim 1 and wherein said substrate is of sapphire.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |