US4719383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric shear wave resonator and method of making same
Assignee: United States Department of Energy
•
Filing: 1986-09-30
•
Granted: 1988-01-12
•
Expires: 2006-09-30
Abstract
Abstract An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppm/°C.
Inventors
- 👤 Jin S. Wang
- 👤 Kenneth M. Lakin
- 👤 Allen R. Landin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:57
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/22; C23C14/34; C23C14/3435; C23C14/225; C23C14/35; H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402; H01J37/3405; H01J37/3408; H03; H03H; H03H3/00; H03H3/007; H03H3/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
A piezoelectric shear wave resonator having a predetermined temperature coefficient of resonance comprising: a composite comprising a first film of piezoelectric material having a 6 mm symmetry, said film having its C-axis substantially inclined at an acute angle with respect to the film normal, such that the shear wave coupling coefficient of said film significantly exceeds the longitudinal wave coupling coefficient of said film, and a second film of p + silicon semiconductor material having a positive temperature coefficient of resonance, and a substrate supporting the composite at its periphery, the ratio of thickness of the semiconductor film to the piezoelectric film determining the temperature coefficient of resonance.
Claim 2
Dependent Claim
108 words
A piezoelectric shear wave resonator having a predetermined temperature coefficient of resonance comprising: a composite comprising a first film of piezoelectric material having a 6 mm symmetry, said film having its C-axis substantially inclined at an acute angle with respect to the film normal, such that the shear wave coupling coefficient of said film significantly exceeds the longitudinal wave coupling coefficient of said film, and a second film of p + silicon semiconductor material having a positive temperature coefficient of resonance, and a substrate supporting the composite at its periphery, the ratio of thickness of the semiconductor film to the piezoelectric film determining the temperature coefficient of resonance.
Claim 3
Dependent Claim
41 words
The resonator of claim 1 wherein the ratio of the thickness of the film of semiconductor material to the thickness of the film of piezoelectric material is predetermined such that the temperature coefficient of resonance of the resonator is 0 ppm/°C.
Claim 4
Dependent Claim
39 words
The shear wave resonator of claim 1 wherein the ratio of thickness of the semiconductor film layer to the piezoelectric film is between 1.5:1 and 10:1 and the temperature coefficient of resonance is about 0 ppm/°C. at room temperature.
Claim 5
Dependent Claim
22 words
The shear wave resonator of claim 3 wherein the piezoelectric material is selected from the group consisting of ZnO, AlN and CdS.
Claim 6
Dependent Claim
25 words
The resonator of claim 4 wherein the angle of inclination of said C-axis with respect to said film normal is between about 40° and 50°.
Claim 7
Dependent Claim
20 words
The resonator of claim 5 wherein the piezoelectric film is ZnO and the ratio is between about 8:1 and 10:1.
Claim 8
Dependent Claim
20 words
The resonator of claim 5 wherein the piezoelectric film is AlN and the ratio is between about 1:5:1 and 3.5:1.
References Cited (Backward Citations)
US3634787A
Cited
JPS58121817A
Cited
JPS58137317A
Cited
US4456850A
Cited
JPS58153412A
Cited
US4556812A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |