US3882430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface acoustic wave devices
Assignee: Thales SA
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Filing: 1974-06-25
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Granted: 1975-05-06
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Expires: 1994-06-25
Abstract
Abstract The surface acoustic wave devices of the invention utilise the reflection of acoustic waves at gratings of irregularly spaced discontinuities, said devices comprising between an input (3) and an output (4) transducer, and gratings (2) of discontinuities, 3 dB directional couplers (5) separating the incident acoustic waves from the delayed reflected acoustic waves and making it possible to create dispersive delay lines and band-pass filters.
Inventors
- 👤 Charles Maerfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:39
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/36; H; H03; H03H; H03H9/00; H03H9/30; H03H9/42; H03H9/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
A surface acoustic wave device comprising a piezo-electric substrate for propagating acoustic waves, an input transducer for converting high frequency electrical waves into acoustic waves for propagating at the surface of said substrate, at least one dispersive grating of non-uniformly spaced discontinuities, and an output transducer for converting the acoustic waves when reflected by said grating, into electrical waves, said grating (2) discontinuities being disposed perpendicularly to the direction of propagation of said acoustic waves, said device further comprising at least one 3 dB coupler (5) of the type having regularly spaced parallel conductive strips arranged between said input (3) and output (4) transducers and said dispersive grating (2), said conductive strips of said coupler (5) being parallel to said discontinuities of said grating (2).
Claim 2
Dependent Claim
125 words
A surface acoustic wave device comprising a piezo-electric substrate for propagating acoustic waves, an input transducer for converting high frequency electrical waves into acoustic waves for propagating at the surface of said substrate, at least one dispersive grating of non-uniformly spaced discontinuities, and an output transducer for converting the acoustic waves when reflected by said grating, into electrical waves, said grating (2) discontinuities being disposed perpendicularly to the direction of propagation of said acoustic waves, said device further comprising at least one 3 dB coupler (5) of the type having regularly spaced parallel conductive strips arranged between said input (3) and output (4) transducers and said dispersive grating (2), said conductive strips of said coupler (5) being parallel to said discontinuities of said grating (2).
Claim 3
Dependent Claim
37 words
A device according to claim 1, wherein said discontinuities of said dispersive grating (2) are mechanical discontinuities constituted by bands engraved at the surface of the piezo-electric material acting as the propagation medium for the acoustic waves.
Claim 4
Dependent Claim
54 words
A device according to claim 1, wherein said discontinuities of said dispersive grating (2) are electrical discontinuities constituted by conductive strips arranged on the surface of the piezo-electric material serving as the propagation medium for the acoustic waves and wherein said grating is in two parts, said conductive strips being interrupted at their centres.
Claim 5
Dependent Claim
23 words
A device according to claim 1 for constituting a dispersive delay line, comprising one dispersive grating (2) and one 3 dB coupler (5).
Claim 6
Dependent Claim
60 words
A device according to claim 1, comprising several dispersive gratings coupled by 3 dB couplers, arranged between the input transducer (3) and the output transducer (4), in the path of the acoustic waves when propagating, said acoustic waves, when delivered by said input transducer (3) successively passing through said dispersive gratings before being picked up by said output transducer (4).
Claim 7
Dependent Claim
76 words
A device according to claim 5, for constituting a dispersive delay line, comprising the same number of dispersive gratings (21, 22, 23) and of 3 dB couplers (51, 52, 53), said dispersive gratings all being arranged in the same fashion in relation to the 3 dB couplers for supplying them with the acoustic wave, so that each of said dispersive gratings delays in thE same way the waves of different frequency which it reflects when operating.
Claim 8
Dependent Claim
105 words
A device according to claim 5, for constituting a band-pass filter, comprising an even number of said dispersive gratings (31, 32) each associated with a 3 dB coupler (51, 52), two gratings of a pair being reversed in relation to one another so that the delay differences introduced by one of them into the acoustic waves of different frequencies which it reflects, when operating, are compensated by the other, the two said 3 dB couplers combined with said dispersive gratings of a pair, themselves being coupled by a third 3 dB coupler (52) with which there is associated a non-dispersive surface wave reflector (33, 34).
References Cited (Backward Citations)
US3836876A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |