US4005376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronically variable surface acoustic wave phase shifter
Assignee: United States Department of the Navy
•
Filing: 1976-04-15
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Granted: 1977-01-25
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Expires: 1996-04-15
Abstract
Abstract An electrically variable surface acoustic wave phase shifter including a strate upon which a piezoelectric layer is deposited and separated therefrom by an insulating layer. An electrode is deposited on the piezoelectric layer and on the bottom of the substrate with an electrical dc bias applied onto the electrodes which causes a charge accumulation or a depletion region at the silicon surface. This charge accumulation or depletion region causes the boundary conditions to change therefore causing a phase change in an acoustical wave propagating along the layered silicon surface.
Inventors
- 👤 Kenneth L. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:11
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/66; H03H9/68
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
An electrically variable surface acoustic wave phase shifter which comprises: a substrate formed of a semiconductor material and having an upper and lower face; a bottom electrode covering the bottom face of said substrate; a thin film of electrically insulating material on the upper face of said substrate; a layer of piezoelectric material deposited onto said thin film of insulating material on said substrate; an upper electrode electrically connected with and covering a portion of said piezoelectric layer; and a variable voltage source for applying a dc bias connected between said upper electrode and said bottom electrode.
Claim 2
Dependent Claim
97 words
An electrically variable surface acoustic wave phase shifter which comprises: a substrate formed of a semiconductor material and having an upper and lower face; a bottom electrode covering the bottom face of said substrate; a thin film of electrically insulating material on the upper face of said substrate; a layer of piezoelectric material deposited onto said thin film of insulating material on said substrate; an upper electrode electrically connected with and covering a portion of said piezoelectric layer; and a variable voltage source for applying a dc bias connected between said upper electrode and said bottom electrode.
Claim 3
Dependent Claim
14 words
A phase shifter as claimed in claim 1 wherein: said semiconductor substrate is silicon.
Claim 4
Dependent Claim
17 words
A phase shifter as claimed in claim 2 wherein: said piezoelectric layer is formed by zinc oxide.
Claim 5
Dependent Claim
22 words
A phase shifter as claimed in claim 3 wherein: said insulating film between said piezoelectric layer and said substrate is silicon dioxide.
Claim 6
Dependent Claim
29 words
A phase shifter as claimed in claim 4 which includes: a thin layer of electrically insulating material on said piezoelectric layer separating said upper electrode from said piezoelectric layer.
References Cited (Backward Citations)
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Cited
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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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |