US4609843A
Expired / Lapsed
US
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Temperature compensated berlinite for surface acoustic wave devices
Assignee: United States Department of the Air Force
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Filing: 1985-02-26
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Granted: 1986-09-02
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Expires: 2005-02-26
Abstract
Abstract The 19.1 propagation X-cut of berlinite (AlPO4) has been discovered to have cubic temperature compensation for surface acoustic waves (SAW). The temperature variations of frequency or time delay over a 35 DEG to 85 DEG C. temperature range are comparable to ST-quartz. However, berlinite has at least twice the piezoelectric coupling. This is essential for low insertion loss, broadband SAW devices such as filters and correlators. In addition, 19.1 propagation, X-cut berlinite has lower volume wave spurious than ST-cut quartz.
Inventors
- 👤 Paul H. Carr
- 👤 Jose H. Silva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:51
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02818; H03H9/02834; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/853
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
141 words
A surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, with transducer means for surface wave coupling which provides cubic temperature compensation, with transducer means perpendicular to the direction of propagation which is 19.1° from the positive X-axis for surface wave coupling, wherein said transducer means comprises interdigital transducers about 2 millimeters apart having a transducer length of about 0.333 millimeters, a linewidth and spacing of about 1.262 micrometers, and an acoustic aperture of about 0.250 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 2
Dependent Claim
141 words
A surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, with transducer means for surface wave coupling which provides cubic temperature compensation, with transducer means perpendicular to the direction of propagation which is 19.1° from the positive X-axis for surface wave coupling, wherein said transducer means comprises interdigital transducers about 2 millimeters apart having a transducer length of about 0.333 millimeters, a linewidth and spacing of about 1.262 micrometers, and an acoustic aperture of about 0.250 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 3
Dependent Claim
29 words
A surface acoustic wave device substrate member according to claim 1 wherein said transducer means comprises 66 double electrode transducers of 60 Å CR and 66 Å Al metallization.
Claim 4
Dependent Claim
143 words
A surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lamda=90.0°, Mu=90.0°, and Theta=19.1°, with transducer means for surface wave coupling which provides cubic temperature compensation, with transducer means perpendicular to the direction of propagation which is 19.1° from the positive X-axis for surface wave coupling, wherein said transducer means comprises interdigital transducers between 3 and 4.5 millimeters apart having a transducer length of about 1.06 millimeters, a linewidth and spacing of about 1.73 micrometers, and an acoustic aperture of about 0.500 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 5
Dependent Claim
143 words
A surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lamda=90.0°, Mu=90.0°, and Theta=19.1°, with transducer means for surface wave coupling which provides cubic temperature compensation, with transducer means perpendicular to the direction of propagation which is 19.1° from the positive X-axis for surface wave coupling, wherein said transducer means comprises interdigital transducers between 3 and 4.5 millimeters apart having a transducer length of about 1.06 millimeters, a linewidth and spacing of about 1.73 micrometers, and an acoustic aperture of about 0.500 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 6
Dependent Claim
29 words
A surface acoustic wave device substrate member according to claim 3, wherein said transducer means comprises 226 double electrode transducers of 60 Å CR and 66 Å Al metallization.
Claim 7
Independent Claim
133 words
A method of using a surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, using the device in an oven at a temperature of about 60° C., and using transducer means for surface wave coupling, said transducer means comprising interdigital transducers about 2 millimeters apart having a transducer length of about 0.333 millimeters, a linewidth and spacing of about 1.262 micrometers, and an acoustic aperture of about 0.250 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 8
Independent Claim
133 words
A method of using a surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, using the device in an oven at a temperature of about 60° C., and using transducer means for surface wave coupling, said transducer means comprising interdigital transducers about 2 millimeters apart having a transducer length of about 0.333 millimeters, a linewidth and spacing of about 1.262 micrometers, and an acoustic aperture of about 0.250 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 9
Independent Claim
135 words
A method of using a surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, using the device in an oven at a temperature of about 60° C., and using transducer means for surface wave coupling, said transducer means comprising interdigital transducers between 3 and 4.5 millimeters apart having a transducer length of about 1.06 millimeters, a linewidth and spacing of about 1.73 micrometers, and an acoustic aperture of about 0.500 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
Claim 10
Independent Claim
135 words
A method of using a surface acoustic wave device substrate member of single crystal berlinite having an acoustic surface wave propagation surface defined by a plane that substantially coincides with the Euler angles Lambda=90.0°, Mu=90.0°, and Theta=19.1°, using the device in an oven at a temperature of about 60° C., and using transducer means for surface wave coupling, said transducer means comprising interdigital transducers between 3 and 4.5 millimeters apart having a transducer length of about 1.06 millimeters, a linewidth and spacing of about 1.73 micrometers, and an acoustic aperture of about 0.500 millimeters, whereby the device provides cubic temperature compensation and a significantly lower bulk wave spurious response compared to ST-cut quartz, the frequency separation between the surface acoustic wave fundamental and the closest bulk wave response being substantially greater than in ST-cut quartz.
References Cited (Backward Citations)
US4012650A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |