US4429246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Group-arranged type surface acoustic wave transducer
Assignee: Toko Inc
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Filing: 1981-12-15
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Granted: 1984-01-31
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Expires: 2001-12-15
Abstract
Abstract A group-arranged type unidirectional surface acoustic wave transducer, which includes, in combination, groups of interdigital electrodes wherein the center-to-center distance between the electrodes is made equal to an integral number of wavelengths plus a quarter wavelength and further groups of interdigital electrodes wherein the center-to-center distance between the electrodes is made equal to an integral number of wavelengths plus three quarter wavelengths. According to the present invention, there is also provided a unidirectional surface acoustic wave device which can be employed as a filter by changing the frequency-amplitude characteristic of the surface acoustic wave.
Inventors
- 👤 Hajime Miyajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:46
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14502; H03H9/14505; H03H9/02535; H03H9/02637; H03H9/02685; H03H9/0274; H03H9/02755
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
A group-arranged type surface acoustic wave transducer including plural groups of two interdigital electrodes having an equal number of electrode finger pairs, connected 90° out of phase with each other, and disposed in such a manner that the center-to-center distance therebetween is equal to an odd number of quarter wavelengths, wherein: the center-to-center distance between the interdigital electrodes in part of said plural groups is made to be equal to an integer number of wavelengths plus a quarter wavelength, and the center-to-center distance between the interdigital electrodes in the remaining groups is made to be equal to an integer number of wavelengths plus three quarter wavelengths.
Claim 2
Dependent Claim
106 words
A group-arranged type surface acoustic wave transducer including plural groups of two interdigital electrodes having an equal number of electrode finger pairs, connected 90° out of phase with each other, and disposed in such a manner that the center-to-center distance therebetween is equal to an odd number of quarter wavelengths, wherein: the center-to-center distance between the interdigital electrodes in part of said plural groups is made to be equal to an integer number of wavelengths plus a quarter wavelength, and the center-to-center distance between the interdigital electrodes in the remaining groups is made to be equal to an integer number of wavelengths plus three quarter wavelengths.
Claim 3
Dependent Claim
73 words
A group-arranged type unidirectional surface acoustic wave transducer according to claim 1, wherein the two interdigital electrodes in each of said plural groups are made equal to each other in terms of the opposing length of the electrode fingers thereof, and the interdigital electrodes in at least one of said plural groups are made different from the interdigital electrodes in the remaining groups in terms of the opposing length of the electrode fingers.
Claim 4
Dependent Claim
70 words
A group-arranged type unidirectional surface acoustic wave transducer according to claim 1, wherein the two interdigital electrodes in each of said plural groups are made equal to each other in terms of the number of electrode finger pairs, and the interdigital electrodes in at least one of said plural groups are made different from the interdigital electrodes in the remaining groups in terms of the number of electrode finger pairs.
References Cited (Backward Citations)
US3727155A
Cited
US3866154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |