US4270105A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized surface wave device
Assignee: Raytheon Co
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Filing: 1979-05-14
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Granted: 1981-05-26
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Expires: 1999-05-14
Abstract
Abstract A surface acoustic wave (SAW) device is provided with short-term and long-term stability by recessing the electrode structure into the surface of the piezoelectric crystal of the device. In addition, the surface is passivated with the silicon polymer, and a cover of the same crystalline material is placed above the electrode structure to prevent absorption of impurities into the surface from the atmosphere. The passivation is believed to reduce the effect of thermal agitation of the bonds of the crystal lattice structure, and thereby prevent the making and breaking of chemical bonds with hydroxyl ions that may have been entrapped from the atmosphere. The SAW device is particularly useful in the construction of stable oscillator circuits wherein the passivation provides improved short-term frequency stability and the cover provides long-term frequency stability.
Inventors
- 👤 Thomas E. Parker
- 👤 Clarence J. Dunnrowicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:29
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/05; H03H9/10; H03H9/1064; H03H9/1092; H03H3/00; H03H3/007; H03H3/08; H03H9/02535; H03H9/02818; H03H9/02929; H03H9/30; H03H9/42
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
46 words
A surface acoustic wave device comprising: a crystalline base; an assembly of electrodes deposited on a surface of said base; and means for passivating said surface comprising a coating deposited on said surface and on said electrode assembly, said coating being formed of a hydrophobic polymer.
Claim 2
Dependent Claim
46 words
A surface acoustic wave device comprising: a crystalline base; an assembly of electrodes deposited on a surface of said base; and means for passivating said surface comprising a coating deposited on said surface and on said electrode assembly, said coating being formed of a hydrophobic polymer.
Claim 3
Dependent Claim
53 words
A surface acoustic wave device comprising: a crystalline base; an assembly of electrodes deposited on a surface of said base; a coating deposited on said surface having said electrode assembly; and said coating being formed of a hydrophobic polymer and having a depth of not more than a few monolayers of said polymer.
Claim 4
Dependent Claim
53 words
A surface acoustic wave device comprising: a crystalline base; an assembly of electrodes deposited on a surface of said base; a coating deposited on said surface having said electrode assembly; and said coating being formed of a hydrophobic polymer and having a depth of not more than a few monolayers of said polymer.
Claim 5
Dependent Claim
82 words
A surface acoustic wave device comprising: a base portion of piezoelectric material, said base portion having a surface supporting an assembly of electrodes; a cover fabricated of said piezoelectric material and in contact with said base portion; and wherein said cover and said base portion provides a gap, between said cover and said base portion, in a region over said electrode assembly to permit the propagation of a sonic wave along the surface of said base portion without interaction with said cover.
Claim 6
Dependent Claim
82 words
A surface acoustic wave device comprising: a base portion of piezoelectric material, said base portion having a surface supporting an assembly of electrodes; a cover fabricated of said piezoelectric material and in contact with said base portion; and wherein said cover and said base portion provides a gap, between said cover and said base portion, in a region over said electrode assembly to permit the propagation of a sonic wave along the surface of said base portion without interaction with said cover.
Claim 7
Dependent Claim
29 words
A device according to claim 3 further comprising: means for passivating said electrode supporting surface of said base portion comprising a polymeric layer deposited on said electrode supporting surface.
Claim 8
Dependent Claim
31 words
A device according to claim 4 wherein said polymeric layer is not more than a few monolayers thick and substantially covers the surface of said piezoelectric material of said base portion.
Claim 9
Dependent Claim
29 words
A device according to claim 5 wherein electrodes of said electrode assembly and at least a portion of each terminal are recessed in said surface of said base portion.
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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) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |