Patent US3659231A successfully refreshed from Google Patents.
US3659231A
Expired / Lapsed
US
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Multi-stage solid-state signal-transmission system
Assignee: Zenith Electronics LLC
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Filing: 1971-03-17
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Granted: 1972-04-25
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Expires: 1991-03-17
Abstract
Abstract Undesired signal feed-through, due to inherent coupling between the input and output transducers of an acousto-electric surfacewave filter, is substantially attenuated by connecting two or more such filters in series and arranging the effective intertransducer spacings so that the sum of feed-through components in the different filters add to a minimum. The required effective spacings are obtained either by using different actual physical spacings of the transducer pairs in the filters, or by providing different acoustic wave propagation velocities in the different stages. In a special case wherein the system consists of three filters in series, time-delayed output signals, due to reflected surface waves, also are compensated.
Inventors
- 👤 Adrian J De Vries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:27
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/64; H03H9/6423; H03H9/6426
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
200 words
A multi-stage solid-stage signal-transmission system comprising: a plurality N of mutually isolated acousto-electric filter stages each comprising an input transducer coupled to an acoustic-wave-propagating medium and responsive to an applied electrical signal of a predetermined center frequency for establishing acoustic waves of a predetermined acoustic wavelength in said medium, and each further comprising an output transducer coupled to said medium and spaced from its associated input transducer in the direction of acoustic-wave propagation therebetween, each output transducer being responsive to acoustic waves in said medium for developing an electrical signal corresponding thereto; coupling means for impressing the electrical signal developed by the output transducer of each stage of said plurality of filter stages on the input transducer of the next successive stage of said plurality of filter stages; and the input and output transducers of each particular one of said plurality of filter stages having an effective spacing in said direction of acoustic-wave propagation of a distance as determined by the equation: where Dn is said distance for the particular stage n of said plurality N of filter stages, Do is any convenient distance, lambda is the wavelength of the center-frequency acoustic wave and Pn is any integer or zero.
Claim 2
Dependent Claim
200 words
A multi-stage solid-stage signal-transmission system comprising: a plurality N of mutually isolated acousto-electric filter stages each comprising an input transducer coupled to an acoustic-wave-propagating medium and responsive to an applied electrical signal of a predetermined center frequency for establishing acoustic waves of a predetermined acoustic wavelength in said medium, and each further comprising an output transducer coupled to said medium and spaced from its associated input transducer in the direction of acoustic-wave propagation therebetween, each output transducer being responsive to acoustic waves in said medium for developing an electrical signal corresponding thereto; coupling means for impressing the electrical signal developed by the output transducer of each stage of said plurality of filter stages on the input transducer of the next successive stage of said plurality of filter stages; and the input and output transducers of each particular one of said plurality of filter stages having an effective spacing in said direction of acoustic-wave propagation of a distance as determined by the equation: where Dn is said distance for the particular stage n of said plurality N of filter stages, Do is any convenient distance, lambda is the wavelength of the center-frequency acoustic wave and Pn is any integer or zero.
Claim 3
Dependent Claim
91 words
A system as defined in claim 1 in which the number N of said filter stages is two and in which the input and output transducers of the second filter stage have an effective spacing in said direction of acoustic-wave propagation differing from the effective spacing between the input and output transducers of the first filter stage by an amount equal to one-half said acoustic wavelength to provide substantial attenuation of spurious signal components attributable to inherent coupling directly between the input and output transducers in each of said filter stages.
Claim 4
Dependent Claim
83 words
A system as defined in claim 1 in which the number N of said filter stages is three, or an integral multiple thereof, and in which the individual different spacings between the input and output transducers of the respective different ones of said filter stages pursuant to said equation provide substantial attenuation of spurious signal components attributable both to acoustic wave reflections in said filter stages and to inherent coupling directly between the input and output stages in each of said filter stages.
References Cited (Backward Citations)
US3582838A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |