Patent EP0181308B1 successfully refreshed from Google Patents.
US3723919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic surface wave filters with reflection suppression
Assignee: Zenith Electronics LLC
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Filing: 1972-03-20
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Granted: 1973-03-27
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Expires: 1992-03-20
Abstract
Abstract A surface-wave integratable filter includes an input transducer for launching acoustic surface waves along a path in a propagating medium. An output transducer responds to those surface waves by developing output signals. One or both transducers takes the form of an iterative series of conductive ribbons disposed laterally across the path. The ribbons are spaced apart by a distance of one-fourth the wavelength of the acoustic energy. A first source or load is connected exclusively across one of a first pair of successive ribbons and one of an adjacent pair of successive ribbons. A second source or load similarly is connected exclusively across the others of the ribbons in those first and second pairs. The center-to-center distance between the ribbons across which each source or load is connected is one-half the acoustic wavelength.
Inventors
- 👤 R Adler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:38
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14502; H03H9/14508
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
175 words
In an acoustic-wave transmitting device having an acousticwave-propagating medium, a first transducer responsive to input signals for launching along a predetermined path in said medium desired acoustic surface waves exhibiting a predetermined wavelength and a second transducer responsive to said desired acoustic waves for developing output signals and also responsive to spurious acoustic-surface waves also of said wavelength in said medium for developing undesired output signal components, the improvement in at least one of said transducers comprising: an iterative series of conductive ribbons individually disposed across said path and laterally spaced one from the next by a center-to-center distance of one-fourth said predetermined wavelength; means for coupling first signal components exclusively across one of a first pair of successive ribbons and one of an adjacent pair of successive ribbons with the center-to-center distance between said pairs being one-half said predetermined wavelength; and means for coupling second signal components exclusively across the other of said ribbons in said first and second pairs with the center-to-center distance between said other ribbons also being one-half said predetermined wavelength.
Claim 2
Dependent Claim
175 words
In an acoustic-wave transmitting device having an acousticwave-propagating medium, a first transducer responsive to input signals for launching along a predetermined path in said medium desired acoustic surface waves exhibiting a predetermined wavelength and a second transducer responsive to said desired acoustic waves for developing output signals and also responsive to spurious acoustic-surface waves also of said wavelength in said medium for developing undesired output signal components, the improvement in at least one of said transducers comprising: an iterative series of conductive ribbons individually disposed across said path and laterally spaced one from the next by a center-to-center distance of one-fourth said predetermined wavelength; means for coupling first signal components exclusively across one of a first pair of successive ribbons and one of an adjacent pair of successive ribbons with the center-to-center distance between said pairs being one-half said predetermined wavelength; and means for coupling second signal components exclusively across the other of said ribbons in said first and second pairs with the center-to-center distance between said other ribbons also being one-half said predetermined wavelength.
Claim 3
Dependent Claim
36 words
A device as defined in claim 1 in which said first-signal-component coupling means includes a first load coupled across said one ribbons, and said second-signal-component coupled means includes a second load coupled across said other ribbons.
Claim 4
Dependent Claim
40 words
A device as defined in claim 2 which further comprises means, incLuding means for shifting the phase of one of said first and second signal components by pi /2 radians, for combining the signals in said first and second loads.
Claim 5
Dependent Claim
64 words
A device as defined in claim 1 in which said first-signal-component coupling means includes a first source of signals of predetermined frequency coupled across said one ribbons, and said second-signal-component coupling means includes a second source of signals, also of said predetermined frequency but shifted in phase by pi /2 radians relative to the signals from said first source, coupled across said other ribbons.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |