Patent US4016440A successfully refreshed from Google Patents.
US4016440A
Expired / Lapsed
US
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Particularly oriented plate-like monocrystalline piezoelectric body and acoustic surface wave filter device employing same
Assignee: Texas Instruments Inc
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Filing: 1975-05-21
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Granted: 1977-04-05
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Expires: 1995-05-21
Abstract
Abstract This disclosure concerns a particularly oriented plate-like monocrystalline piezoelectric body of lithium niobate for use as a substrate in an acoustic surface wave filter device, wherein the orientation of the piezoelectric body of lithium niobate is responsible for a substantial reduction in spurious responses including plate modes. More specifically, the piezoelectric body comprises a plate of lithium niobate having a crystalline lattice orientation as determined by a 46° (ZYW) cut. It has been determined that such a piezoelectric body may be employed as a substrate in an acoustic surface wave filter device to effect an improved filter response in that unwanted spurious responses including those caused by plate modes are removed or substantially reduced from the acoustic signals prior to their conversion into electrical output signals.
Inventors
- 👤 Robert S. Wagers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:54
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02559
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
66 words
A piezoelectric body for use as a substrate in an acoustic surface wave filter device, said body comprising a monocrystalline member of lithium niobate of plate-like configuration and having a crystalline lattice orientation determined by a cut lying within the range of 60° - 30° (ZYW) cut so as to substantially limit the number of plate modes available for coupling, thereby enhancing the plate mode discrimination.
Claim 2
Dependent Claim
66 words
A piezoelectric body for use as a substrate in an acoustic surface wave filter device, said body comprising a monocrystalline member of lithium niobate of plate-like configuration and having a crystalline lattice orientation determined by a cut lying within the range of 60° - 30° (ZYW) cut so as to substantially limit the number of plate modes available for coupling, thereby enhancing the plate mode discrimination.
Claim 3
Dependent Claim
29 words
A piezoelectric body as set forth in claim 1, wherein the crystalline lattice orientation of said plate-like monocrystalline member of lithium niobate is determined by a 46° (ZYW) cut.
Claim 4
Dependent Claim
99 words
An acoustic surface wave filter device comprising a substrate of piezoelectric material, acoustic surface wave transducer means disposed on said substrate and responsive to an electrical input signal to propagate acoustic surface waves in said substrate, and said substrate being a monocrystalline plate-like body of lithium niobate having a crystalline lattice orientation as determined by a cut lying within the range of 60° - 30° (ZYW) cut so as to substantially limit the number of plate modes available for coupling upon excitation of said acoustic surface wave transducer means by the electrical input signal, thereby enhancing plate mode discrimination.
Claim 5
Dependent Claim
99 words
An acoustic surface wave filter device comprising a substrate of piezoelectric material, acoustic surface wave transducer means disposed on said substrate and responsive to an electrical input signal to propagate acoustic surface waves in said substrate, and said substrate being a monocrystalline plate-like body of lithium niobate having a crystalline lattice orientation as determined by a cut lying within the range of 60° - 30° (ZYW) cut so as to substantially limit the number of plate modes available for coupling upon excitation of said acoustic surface wave transducer means by the electrical input signal, thereby enhancing plate mode discrimination.
Claim 6
Dependent Claim
73 words
An acoustic surface wave filter device as set forth in claim 3, wherein said acoustic surface wave transducer means comprises input and output interdigital transducers disposed on said substrate in spaced apart relationship, said input interdigital transducer being responsive to an electrical input signal to propagate acoustic surface waves in said substrate, and said output interdigital transducer being responsive to acoustic surface waves propagated in said substrate to generate an electrical output signal.
Claim 7
Dependent Claim
32 words
An acoustic surface wave filter device as set forth in claim 4, wherein the crystalline lattice orientation of said plate-like monocrystalline substrate of lithium niobate is determined by a 46° (ZYW) cut.
References Cited (Backward Citations)
US3601639A
Cited
US3906410A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |