US4342012A
Expired / Lapsed
US
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Surface acoustic wave device
Assignee: Panasonic Holdings Corp
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Filing: 1981-02-18
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Granted: 1982-07-27
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Expires: 2001-02-18
Abstract
Abstract A surface acoustic wave device in which an X-cut LiTaO 3 single crystal substrate has its one major surface coated with a SiO 2 film and the direction of propagation of surface acoustic waves is selected between 80° and 180° measured from the Y-axis toward the Z-axis. The surface acoustic wave devices in accordance with the present invention has an extremely low temperature coefficient change and a high electro-mechanical coupling coefficient, exhibits a higher degree of both short- and long-term stability, and can suppress the generation of unwanted waves to a minimum or negligible degree.
Inventors
- 👤 Ritsuo Inaba
- 👤 Kiyotaka Wasa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:24
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02559
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
57 words
A surface acoustic wave device comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over one major surface of said substrate, and interdigital electrodes formed over said major surface and oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 2
Dependent Claim
57 words
A surface acoustic wave device comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over one major surface of said substrate, and interdigital electrodes formed over said major surface and oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 3
Dependent Claim
45 words
A surface acoustic wave device as set forth in claim 1 further characterized in that the product h.k is between 0.6 and 3.0, where h is the thickness of the SiO 2 film and k is equal to 2π/λ where λ is acoustic wave length.
Claim 4
Dependent Claim
72 words
A delay line device comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed over one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 5
Dependent Claim
72 words
A delay line device comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed over one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 6
Dependent Claim
60 words
A delay line device comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 7
Dependent Claim
60 words
A delay line device comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 8
Dependent Claim
47 words
A delay line device as set forth in claim 3 or claim 4 further characterized in that the product h.k is between 0.6 and 3.0, where h is the thickness of said SiO 2 film and k is equal to 2π/λ where λ is acoustic wave length.
Claim 9
Dependent Claim
66 words
A bandpass filter comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed on one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes thereon, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 10
Dependent Claim
66 words
A bandpass filter comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed on one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes thereon, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 11
Dependent Claim
59 words
A bandpass filter comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 12
Dependent Claim
59 words
A bandpass filter comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 13
Dependent Claim
46 words
A bandpass filter as set forth in claim 6 or claim 7 further characterized in that the product h.k is between 0.6 and 3.0, where h is the thickness of said SiO 2 film and k is equal to 2π/λ where λ is acoustic wave length.
Claim 14
Dependent Claim
80 words
An oscillator comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed on one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes thereon, a connecting means for electrically interconnecting between the input and output of said interdigital electrodes, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 15
Dependent Claim
80 words
An oscillator comprising an X-cut LiTaO 3 single crystal substrate, interdigital electrodes formed on one major surface of said substrate, a SiO 2 film formed over said one major surface of said substrate and said interdigital electrodes thereon, a connecting means for electrically interconnecting between the input and output of said interdigital electrodes, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 16
Dependent Claim
72 words
An oscillator comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, a connecting means for electrically interconnecting the input to output of said interdigital electrodes, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 17
Dependent Claim
72 words
An oscillator comprising an X-cut LiTaO 3 single crystal substrate, a SiO 2 film formed over said one major surface of said substrate, interdigital electrodes formed on said SiO 2 film, a connecting means for electrically interconnecting the input to output of said interdigital electrodes, and said electrodes being oriented such that the direction of propagation of surface acoustic waves is between 80° and 180° measured from the Y-axis toward the Z-axis.
Claim 18
Dependent Claim
45 words
An oscillator as set forth in claim 9 or claim 10 further characterized in that the product h.k is between 0.6 and 3.0, where h is the thickness of said SiO 2 film and k is equal to 2π/λ where λ is acoustic wave length.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-26 | 1986-01-25 | 1986-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-26 | 1990-01-25 | 1990-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-26 | 1994-01-25 | 1994-07-27 | $7700.00 | Window Closed / Lapsed |