Patent US2484283A successfully refreshed from Google Patents.
Patent US4298849A successfully refreshed from Google Patents.
US4298849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duall-passband surface acoustic wave filter
Assignee: CTS Corp
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Filing: 1979-10-15
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Granted: 1981-11-03
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Expires: 1999-10-15
Abstract
Abstract A three-transducer SAW filter is disclosed that includes a central input transducer requiring only one-half of the interdigital fingers normally required by prior art three-transducer SAW filters. As a result, two input transducers may now be provided in the space normally occupied by one prior art input transducer. The only requirement is that each input transducer have an axis of symmetry about which surface waves are propogated symmetrically. Since each input transducer may have a different frequency response, a dual-passband SAW filter may now be provided in the space normally occupied by a single prior art SAW filter. Furthermore, a multi-passband SAW filter may be provided by arranging pairs of input transducers between three or more output transducers which are electrically coupled in parallel. In addition, the input and output connections of a multi-passband SAW filter may be interchanged such that an input signal, applied to the parallel connected output transducers is frequency sorted by the passbands of each of the input transducers.
Inventors
- 👤 Steven H. Arneson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:58
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/70; H03H9/72; H03H9/02; H03H9/02535; H03H9/02637; H03H9/02685; H03H9/02692; H03H9/027; H03H9/125; H03H9/145; H03H9/14502; H03H9/14505; H03H9/14544; H03H9/1455; H03H2250/00; H03H9/14517; H03H9/1452
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
127 words
A surface acoustic wave (SAW) filter, comprising: a piezoelectric substrate having at least one surface; first and second transducer means disposed on the surface of the substrate at a predetermined distance from one another, the first and second transducer means each having a plurality of interdigital fingers; and third and fourth non-identical transducer means disposed on the surface of the substrate between the first and second transducer means, the substrate having an axis located substantially equidistant between the first and second transducer means, and the third transducer means including a plurality of interdigital fingers disposed substantially to one side of the substrate axis, and the fourth transducer means including a plurality of interdigital fingers disposed substantially to the side opposite said one side of the substrate axis.
Claim 2
Dependent Claim
127 words
A surface acoustic wave (SAW) filter, comprising: a piezoelectric substrate having at least one surface; first and second transducer means disposed on the surface of the substrate at a predetermined distance from one another, the first and second transducer means each having a plurality of interdigital fingers; and third and fourth non-identical transducer means disposed on the surface of the substrate between the first and second transducer means, the substrate having an axis located substantially equidistant between the first and second transducer means, and the third transducer means including a plurality of interdigital fingers disposed substantially to one side of the substrate axis, and the fourth transducer means including a plurality of interdigital fingers disposed substantially to the side opposite said one side of the substrate axis.
Claim 3
Dependent Claim
34 words
The SAW filter according to claim 1, wherein the interdigital fingers of said first and second transducer means are substantially identically arranged, and said first and second transducer means are electrically coupled in parallel.
Claim 4
Dependent Claim
61 words
The SAW filter according to claim 2, further adapted to receive first and second input signals, the first input signal coupled to one of, and the second input signal coupled to the other of, the third and fourth transducer means, and the first and second transducer means providing a composite output signal comprised of the filtered first and second input signals.
Claim 5
Dependent Claim
53 words
The SAW filter according to claim 3, further adapted to receive a radio-frequency (RF) signal and a receiver injection signal from an RF receiver having mixing circuitry, the first and second input signals being the RF signal and receiver injection signal and the composite output signal being coupled to the receiver mixing circuitry.
Claim 6
Dependent Claim
39 words
The SAW filter according to claim 2, further including a plurality of semicircular coupling strips disposed around each of the first and second transducer means for substantially unidirectionally coupling surface acoustic waves to the first and second transducer means.
Claim 7
Dependent Claim
115 words
The SAW filter according to claim 2, further including fifth transducer means disposed at a predetermined distance from one of the first and second transducer means, and further including sixth and seventh transducer means, said substrate having a second axis located substantially equidistant between said one of the first and second transducer means and the fifth transducer means, the sixth and seventh transducer means each having a plurality of interdigital fingers arranged such that the interdigital fingers of the sixth transducer means are disposed substantially to one side of the second axis and the interdigital fingers of the seventh transducer means are disposed substantially to the side opposite said one side of the second axis.
Claim 8
Dependent Claim
28 words
The SAW filter according to claim 6, wherein the interdigital fingers of said first, second and fifth transducer means are substantially identically arranged and electrically coupled in parallel.
Claim 9
Dependent Claim
45 words
The SAW filter according to claim 2, further adapted to receive an input signal, the input signal coupled to the first and second transducer means, and the third and fourth transducer means frequency sorting the input signal to provide first and second output signals, respectively.
Claim 10
Dependent Claim
148 words
A surface acoustic wave (SAW) filter, comprising: a piezoelectric substrate having at least one surface; first and second transducer means disposed on the surface of the substrate at a predetermined distance from one another, the first and second transducer means being electrically coupled in parallel and each having a plurality of parallel interdigital fingers; and third and fourth transducer means disposed on the surface of the substrate between the first and second transducer means, the substrate having an axis located substantially equidistant between said first and second transducer means, and the third and fourth transducer means each having a plurality of parallel interdigital fingers arranged such that the interdigital fingers of the third transducer means are disposed substantially to one side of the substrate axis and the interdigital fingers of the fourth transducer means are disposed substantially to the side opposite said one side of the substrate axis.
Claim 11
Dependent Claim
148 words
A surface acoustic wave (SAW) filter, comprising: a piezoelectric substrate having at least one surface; first and second transducer means disposed on the surface of the substrate at a predetermined distance from one another, the first and second transducer means being electrically coupled in parallel and each having a plurality of parallel interdigital fingers; and third and fourth transducer means disposed on the surface of the substrate between the first and second transducer means, the substrate having an axis located substantially equidistant between said first and second transducer means, and the third and fourth transducer means each having a plurality of parallel interdigital fingers arranged such that the interdigital fingers of the third transducer means are disposed substantially to one side of the substrate axis and the interdigital fingers of the fourth transducer means are disposed substantially to the side opposite said one side of the substrate axis.
Claim 12
Dependent Claim
61 words
The SAW filter according to claim 9, further adapted to receive first and second input signals, the first input signal coupled to one of, and the second input signal coupled to the other of, the third and fourth transducer means, and the first and second transducer means providing a composite output signal comprised of the filtered first and second input signals.
Claim 13
Dependent Claim
61 words
The SAW filter according to claim 10, further including a second SAW filter substantially the same as the first SAW filter, and arranged together with the first SAW filter, such that the composite output signal from the first and second transducer means of the first SAW filter is coupled to the third and fourth transducer means of the second SAW filter.
Claim 14
Dependent Claim
61 words
The SAW filter according to claim 10, further including a second SAW filter substantially the same as the first SAW filter, and arranged together with the first SAW filter, such that the composite output signal from the first and second transducer means of the first SAW filter is coupled to the first and second transducer means of the second SAW filter.
Claim 15
Dependent Claim
53 words
The SAW filter according to claim 10, further adapted to receive a radio-frequency (RF) signal and a receiver injection signal from an RF receiver having mixing circuitry, the first and second input signals being the RF signal and receiver injection signal and the composite output signal being coupled to the receiver mixing circuitry.
Claim 16
Dependent Claim
39 words
The SAW filter according to claim 9, further including a plurality of semicircular coupling strips disposed around each of the first and second transducer means for substantially unidirectionally coupling surface acoustic waves to the first and second transducer means.
Claim 17
Dependent Claim
123 words
The SAW filter according to claim 9, further including fifth transducer means disposed at a predetermined distance from, and electrically coupled in parallel with, one of the first and second transducer means, and further including sixth and seventh transducer means, said substrate having a second axis located substantially equidistant between said one of the first and second transducer means and the fifth transducer means, the sixth and seventh transducer means each having a plurality of parallel interdigital fingers arranged such that the interdigital fingers of the sixth transducer means are disposed substantially to one side of the second axis and the interdigital digital fingers of the seventh transducer means are disposed substantially to the side opposite said one side of the second axis.
Claim 18
Dependent Claim
45 words
The SAW filter according to claim 9, further adapted to receive an input signal, the input signal coupled to the first and second transducer means, and the third and fourth transducer means frequency sorting the input signal to provide first and second output signals, respectively.
Claim 19
Dependent Claim
227 words
A multi-passband surface acoustic wave (SAW) filter adapted to filter and combine first and second input signals, comprising: a piezoelectric substrate having at least one surface, first and second input transducers each having a plurality of parallel interdigital fingers disposed at a predetermined spacing therebetween, said substrate further having an axis located between the first and second input transducers, the first and second input transducers arranged on the surface of the substrate such that the interdigital fingers of the first input transducer are disposed substantially to one side of the substrate axis and the interdigital fingers of the second input transducer are disposed substantially to the side opposite said one side of the substrate axis, and the first and second transducers further being adapted to receive the first and second input signals, respectively; and first and second output transducers disposed on the surface of the substrate on opposite sides of, and substantially equidistant from, the substrate axis, the first and second output transducers each having a plurality of parallel interdigital fingers disposed at a predetermined spacing therebetween and arranged parallel to the interdigital fingers of the first and second input transducers, and the first and second output transducers further being electrically coupled in parallel for combining the filtered first and second input signals received from the first and second input transducers to provide a composite output signal.
Claim 20
Dependent Claim
227 words
A multi-passband surface acoustic wave (SAW) filter adapted to filter and combine first and second input signals, comprising: a piezoelectric substrate having at least one surface, first and second input transducers each having a plurality of parallel interdigital fingers disposed at a predetermined spacing therebetween, said substrate further having an axis located between the first and second input transducers, the first and second input transducers arranged on the surface of the substrate such that the interdigital fingers of the first input transducer are disposed substantially to one side of the substrate axis and the interdigital fingers of the second input transducer are disposed substantially to the side opposite said one side of the substrate axis, and the first and second transducers further being adapted to receive the first and second input signals, respectively; and first and second output transducers disposed on the surface of the substrate on opposite sides of, and substantially equidistant from, the substrate axis, the first and second output transducers each having a plurality of parallel interdigital fingers disposed at a predetermined spacing therebetween and arranged parallel to the interdigital fingers of the first and second input transducers, and the first and second output transducers further being electrically coupled in parallel for combining the filtered first and second input signals received from the first and second input transducers to provide a composite output signal.
Claim 21
Dependent Claim
237 words
The multi-passband SAW filter of claim 17 further adapted to filter and combine first, second, third and fourth input signals, wherein said multi-passband SAW filter further includes a third output transducer disposed at a predetermined distance from, and electrically coupled in parallel with, one of the first and second output transducers; and said filter further includes third and fourth input transducers adapted to receive the third and fourth input signals, respectively, the third and fourth input transducers disposed on the surface of the substrate between said one of the first and second output transducers and the third output transducer, the third and fourth input transducers having collinear axes of symmetry located substantially equidistant between said one of the first and second output transducers and the third output transducer, and the third and fourth input transducers each having a plurality of parallel interdigital fingers disposed at a predetermined spacing therebetween and arranged such that the interdigital fingers of the third input transducer are disposed substantially to one side of the collinear axes of symmetry of the third and fourth input transducers and the interdigital fingers of the fourth input transducer are disposed substantially to the side opposite said one side of the collinear axes of symmetry of the third and fourth input transducers, and the composite signal provided by the first, second and third output transducers being comprised of the filtered first, second, third and fourth input signals.
References Cited (Backward Citations)
US3582838A
Cited
US3582840A
Cited
US3600710A
Cited
US3836876A
Cited
US3921093A
Cited
US3859608A
Cited
US3970970A
Cited
GB1517371A
Cited
SU585589A1
Cited
US4044321A
Cited
US4063202A
Cited
US4047130A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |