US3582840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic wave filter
Assignee: Zenith Electronics LLC
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Filing: 1969-03-20
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Granted: 1971-06-01
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Expires: 1989-03-20
Abstract
Abstract A body of piezoelectric material propagates acoustic surface waves. A central transducer is coupled to a surface of the body to interact with those waves. Spaced on the same surface generally symmetrically individually with respect to that central transducer are a pair of outer transducers. Each of the three transducers includes interleaved combs of conductive electrodes that are spaced apart effectively by one-half the approximate wavelength of the surface waves. The combs of the outer transducers are mutually arranged, relative to the central transducers, such that surface waves propagating between the central and one of the outer transducers create electrical signals additively related in phase to electrical signals created by surface waves propagating between the central and the other outer transducers. In the several illustrated species, the specific arrangement of the different combs varies in dependence upon the number of individual comb electrodes in the different transducers and the choice as between series or parallel interconnection of the outer transducers.
Inventors
- 👤 Adrian J Devries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:38
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/0023; H03H9/0028; H03H9/0033; H03H9/0038; H03D; H03D3/00; H03D3/02; H03D3/06; H03D3/16; H03H9/0042; H03H9/02; H03H9/125; H03H9/145; H03H9/14544; H03H9/1455; H03H9/46; H03H9/64; H03H9/6423
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
151 words
In an acoustic filter having an acoustic-wave-propagating medium, a central surface-wave transducer actively coupled to a first surface portion of said medium and a pair of outer surfacewave transducers actively coupled individually to respective second and third surface portions of said medium mutually spaced in opposite directions from said first portion with each of said transducers composed of interleaved combs of conductive electrodes mutually spaced apart effectively by one-half the approximate wavelength of transmitted signals, the improvement comprising: means for interconnecting said outer transducers; connecting means for coupling input and output signals to and from said transducers; and the combs of said outer transducers being mutually arranged, relative to said central transducer, such that surface waves propagating between said central transducer and one of said outer transducers create electrical signals cumulatively phasecorrelated with electrical signals created by surface waves propagating between said central transducer and the other of said outer transducers.
Claim 2
Dependent Claim
151 words
In an acoustic filter having an acoustic-wave-propagating medium, a central surface-wave transducer actively coupled to a first surface portion of said medium and a pair of outer surfacewave transducers actively coupled individually to respective second and third surface portions of said medium mutually spaced in opposite directions from said first portion with each of said transducers composed of interleaved combs of conductive electrodes mutually spaced apart effectively by one-half the approximate wavelength of transmitted signals, the improvement comprising: means for interconnecting said outer transducers; connecting means for coupling input and output signals to and from said transducers; and the combs of said outer transducers being mutually arranged, relative to said central transducer, such that surface waves propagating between said central transducer and one of said outer transducers create electrical signals cumulatively phasecorrelated with electrical signals created by surface waves propagating between said central transducer and the other of said outer transducers.
Claim 3
Dependent Claim
62 words
A filter as defined in claim 1 in which said outer transducers are connected in paraLlel, in which said central transducer has an even number of said electrodes and in which said one outer transducer is disposed to define a transformation of said other outer transducer by rotation in the plane of said surface about the geometrical center of said central transducer.
Claim 4
Dependent Claim
77 words
A filter as defined in claim 1 in which said outer transducers are connected in parallel, in which said central transducer has an odd number of said electrodes and in which said one outer transducer is disposed to define a transformation of said other outer transducer by rotation in the plane of said surface about the geometrical center of said central transducer and inversion about a line in said plane perpendicular to the teeth in said combs.
Claim 5
Dependent Claim
61 words
A filter as defined in claim 1 in which said outer transducers are connected in series, in which said central transducer has an odd number of electrodes and in which said one outer transducer is disposed to define a transformation of said other outer transducer by rotation in the plane of said surface about the geometrical center of said central transducer.
Claim 6
Dependent Claim
77 words
A filter as defined in claim 1 in which said outer transducers are connected in series, in which said central transducer has an even number of electrodes and in which said one outer transducer is disposed to define a transformation of said other outer transducer device by rotation in the plane of said surface about the geometrical center of said central transducer and inversion about a line in said plane perpendicular to the teeth in said combs.
Claim 7
Dependent Claim
50 words
A filter is defined in claim 1 in which said central transducer has an odd number of electrodes and interacts with oppositely directed like-phased waves, the electrodes of said outer transducers being disposed and distributed to define induced signal phase patterns effectively mutually symmetrical with respect to said central transducer.
Claim 8
Dependent Claim
50 words
A filter as defined in claim 1 in which said central transducer has an even number of electrodes and interacts with oppositely directed antiphased waves, the electrodes of said outer transducers being disposed and distributed to define induced signal phase patterns effectively mutually asymmetrical with respect to said central transducer.
Claim 9
Dependent Claim
72 words
A filter as defined in claim 1 which further includes a fourth surface-wave transducer actively coupled to a fourth surface portion on the opposite side of said one transducer from said central transducer and a fifth surface-wave transducer actively coupled to a fifth surface portion on the opposite side of said fourth transducer from said one transducer, said central and fourth transducers and said one and said fifth transducers being respectively interconnected.
Claim 10
Dependent Claim
29 words
A filter as defined in claim 8 in which said central and fourth transducers are interconnected in series and said outer and fifth transducers also are interconnected in series.
Claim 11
Dependent Claim
29 words
A filter as defined in claim 8 in which said central and fourth transducers are interconnected in parallel and said outer and fifth transducers also are interconnected in parallel.
Claim 12
Dependent Claim
28 words
A filter as defined in claim 8 in which said central and fourth transducers are interconnected in series and said outer and fifth transducers are interconnected in parallel.
Claim 13
Dependent Claim
40 words
A filter as defined in claim 1 in which said interconnecting means is disposed along said surface on at least one side of said transducers and said connecting means is disposed on said surface on both sides of said transducers.
Claim 14
Dependent Claim
140 words
An acoustic filter system comprising: a body of piezoelectric material propagative of acoustic surface waves; at least three surface wave interaction devices actively coupled to assigned surface portions of said body, separated from one another in the direction of surface wave propagation and individually comprising a pair of comblike electrode arrays with the electrode elements of one array interleaved with those of the other and spaced from one another by one-half the acoustic wavelength of a predetermined siGnal frequency to have a maximum interaction with said body at said predetermined frequency; means for applying a signal to the centrally located one of said devices to launch acoustic surface waves to said body; and means coupled to the remaining pair of interaction devices for deriving from the launched acoustic surface waves phase correlated and cumulative energy for application to a load.
Claim 15
Dependent Claim
140 words
An acoustic filter system comprising: a body of piezoelectric material propagative of acoustic surface waves; at least three surface wave interaction devices actively coupled to assigned surface portions of said body, separated from one another in the direction of surface wave propagation and individually comprising a pair of comblike electrode arrays with the electrode elements of one array interleaved with those of the other and spaced from one another by one-half the acoustic wavelength of a predetermined siGnal frequency to have a maximum interaction with said body at said predetermined frequency; means for applying a signal to the centrally located one of said devices to launch acoustic surface waves to said body; and means coupled to the remaining pair of interaction devices for deriving from the launched acoustic surface waves phase correlated and cumulative energy for application to a load.
Claim 16
Dependent Claim
25 words
An acoustic filter system in accordance with claim 13 in which said interaction devices have maximum interaction with said body at a common predetermined frequency.
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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |