Patent US3980904A successfully refreshed from Google Patents.
US3980904A
Expired / Lapsed
US
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Elastic surface wave device
Assignee: Toshiba Corp
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Filing: 1974-10-24
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Granted: 1976-09-14
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Expires: 1994-10-24
Abstract
Abstract An elastic surface wave device comprises a piezoelectric body and interdigital type electric signal-surface wave conversion conductors formed one at each end portion of one surface of the piezoelectric body. A groove elongated in a surface wave propagation direction is provided in a surface opposite to the surface on which the conversion conductors are formed.
Inventors
- 👤 Toshihiro Onodera
- 👤 Shigehumi Morishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:01
CPC Classifications
H; H04; H04R; H04R17/00; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02614; H03H9/02622; H03H9/02818; H03H9/02866
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
An elastic surface wave device comprising a piezoelectric body and input and output conductors formed on the piezoelectric body and consisting of a pair of multi-fingered electrodes insulated from each other, arranged close to each other in an interdigital fashion and adapted to effect conversion between electric signal and a surface wave, said piezoelectric body having at least one groove formed in a surface opposite to the surface on which the conductor is formed, said groove being elongated in a direction in which a surface wave is propagated and at least a part of said groove being located in a portion of said body corresponding to the input conduction so as to interact with a surface wave and suppress spurious responses.
Claim 2
Dependent Claim
121 words
An elastic surface wave device comprising a piezoelectric body and input and output conductors formed on the piezoelectric body and consisting of a pair of multi-fingered electrodes insulated from each other, arranged close to each other in an interdigital fashion and adapted to effect conversion between electric signal and a surface wave, said piezoelectric body having at least one groove formed in a surface opposite to the surface on which the conductor is formed, said groove being elongated in a direction in which a surface wave is propagated and at least a part of said groove being located in a portion of said body corresponding to the input conduction so as to interact with a surface wave and suppress spurious responses.
Claim 3
Dependent Claim
53 words
An elastic surface wave device according to claim 1 in which said input and output conductors are located in a spaced-apart relation on one surface of said piezoelectric body and said groove is formed in a surface opposite to the surface on which either one of the input and output conductors is formed.
Claim 4
Dependent Claim
56 words
An elastic surface wave device according to claim 1 in which said input and output conductors are provided through a piezoelectric film on one surface of a surface wave propagation medium, and a groove elongated in a surface wave propagation direction is formed in a surface opposite to the surface on which the conductor is provided.
Claim 5
Dependent Claim
62 words
An elastic surface wave device according to claim 1 in which piezoelectric bodies are provided through the conductor on one surface of a surface wave propagation medium and a groove elongated in a surface wave propagation direction is formed on the surface of at least one of the piezoelectric body and surface wave propagation medium which is not contacted with the conductor.
Claim 6
Dependent Claim
29 words
An elastic surface wave device according to claim 1 in which an angle at which the groove is made to the surface wave propagation direction is less than 45°.
Claim 7
Dependent Claim
25 words
An elastic surface wave device according to claim 1 in which the groove is formed in a direction parallel to the surface wave propagation direction.
Claim 8
Dependent Claim
32 words
An elastic surface wave device according to claim 1 in which the depth of the groove is more than 0.01 λsh in which λsh denotes the wavelength of spurious signals (bulk mode).
Claim 9
Dependent Claim
49 words
An elastic surface wave device according to claim 1 in which the depth of the groove is so formed as to satisfy an equation ##EQU1## in which h denotes the depth of the groove, l denotes the length of the groove, and m denotes the width of the substrate.
Claim 10
Dependent Claim
33 words
An elastic surface wave device according to claim 1 in which the width of the groove is equal to more than 5% of an overlapped length of the finger of the interdigital conductor.
Claim 11
Dependent Claim
28 words
An elastic surface wave device according to claim 1 in which the width of the groove is half the overlapped length of the finger of the interdigital conductor.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |