US4245201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elastic surface wave device
Assignee: Toshiba Corp
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Filing: 1978-11-22
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Granted: 1981-01-13
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Expires: 1998-11-22
Abstract
Abstract An elastic surface wave device includes a transducer having an elastic surface wave propagated in the direction of 75 to 133 degrees to a Y-axis on an X-cut lithium tantalate (LiTaO 3 ) substrate.
Inventors
- 👤 Sadao Takahashi
- 👤 Hitoshi Hirano
- 👤 Sadao Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:12
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/36; H; H03; H03H; H03H3/00; H03H3/007; H03H3/08; H03H3/10; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02559
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
156 words
An intermediate frequency filter for television receivers having a passband of less than about 5 MHz, improved temperature stability and improved adjacent channel spurious response suppression, including an elastic surface wave device comprising: at least one transducer having an elastic surface wave propagated in a direction of (112°±10°) or (112°±180°±10°) to a Y-axis on an X-cut lithium tantalate (LiTaO 3 ) substrate, in which said LiTaO 3 crystal is vertically X-cut at an angle of ±10° from the substrate based on the IRE standard and said Y-axis based on the IRE standard is an axis projected on the X-cut substrate; a pair of spaced apart signal electrodes on said substrate and aligned in said propagation direction, an elastic surface wave propagating in said transducer from one of said electrodes to the other responsive to an applied signal; and said transducer having dimensions such that the passband width of the filter is less than about 5 MHz.
Claim 2
Dependent Claim
156 words
An intermediate frequency filter for television receivers having a passband of less than about 5 MHz, improved temperature stability and improved adjacent channel spurious response suppression, including an elastic surface wave device comprising: at least one transducer having an elastic surface wave propagated in a direction of (112°±10°) or (112°±180°±10°) to a Y-axis on an X-cut lithium tantalate (LiTaO 3 ) substrate, in which said LiTaO 3 crystal is vertically X-cut at an angle of ±10° from the substrate based on the IRE standard and said Y-axis based on the IRE standard is an axis projected on the X-cut substrate; a pair of spaced apart signal electrodes on said substrate and aligned in said propagation direction, an elastic surface wave propagating in said transducer from one of said electrodes to the other responsive to an applied signal; and said transducer having dimensions such that the passband width of the filter is less than about 5 MHz.
Claim 3
Dependent Claim
27 words
An intermediate frequency filter according to claim 1 having an elastic surface wave propagation direction of about 112.2° to the Y-axis of said X-cut lithium tantalate substrate.
Claim 4
Dependent Claim
24 words
An intermediate frequency filter according to claim 1 wherein said elastic surface wave propagation direction is within a range of from 110.2° to 112.2°.
Claim 5
Dependent Claim
27 words
An intermediate frequency filter according to claim 1 having an elastic surface wave propagation direction of about 292.2° to the Y-axis of said X-cut lithium tantalate substrate.
Claim 6
Dependent Claim
24 words
An intermediate frequency filter according to claim 1 wherein said elastic surface wave propagation direction is within a range of from 290.2° to 292.2°.
Claim 7
Dependent Claim
15 words
An intermediate frequency filter wave according to claim 1 wherein said electrodes comprise interdigital electrodes.
Claim 8
Dependent Claim
26 words
An intermediate frequency filter according to claim 6 wherein said interdigital electrodes comprise a plurality of elongate digit electrodes oriented substantially perpendicularly to said propagation direction.
References Cited (Backward Citations)
US3818382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |