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US4146808A
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Thinned withdrawal weighted surface acoustic wave interdigital transducers
Assignee: United States Department of the Air Force
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Filing: 1977-11-10
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Granted: 1979-03-27
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Expires: 1997-11-10
Abstract
Abstract Passband distortion due to mass loading in withdrawal weighted surface acoustic wave transducers is substantially reduced by a thinning technique in which interdigital transducer electrodes are selectively withdrawn to synthesize a response function H o '(N). H o '(N) is a modified response function that has been scaled from a desired response function H o (N) by a thinning factor THIN. THIN is a positive, non-zero constant with a maximum value of unity. Thinned withdrawal weighted transducers fabricated in accordance with the technique have electrode weights that are normalized to less than unity and achieve mass loading reduction with a minimum amount of degradation of the desired response function.
Inventors
- 👤 Kenneth R. Laker
- 👤 Thomas L. Szabo
- 👤 Andrew J. Slobodnik, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:22
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14517; H03H9/14526
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A method for fabricating a surface acoustic wave interdigital transducer comprising the steps of defining a preselected response function H o (N), selecting a thinning factor THIN, said thinning factor THIN being a positive non-zero number with a maximum value of less than unity, scaling said response function H o (N) by said thinning factor to provide a modified response function H o '(N), fabricating an interdigital transducer having opposing sets of overlapping electrodes, and withdrawing electrodes to synthesize said modified response function H o '(N).
Claim 2
Independent Claim
86 words
A method for fabricating a surface acoustic wave interdigital transducer comprising the steps of defining a preselected response function H o (N), selecting a thinning factor THIN, said thinning factor THIN being a positive non-zero number with a maximum value of less than unity, scaling said response function H o (N) by said thinning factor to provide a modified response function H o '(N), fabricating an interdigital transducer having opposing sets of overlapping electrodes, and withdrawing electrodes to synthesize said modified response function H o '(N).
Claim 3
Dependent Claim
38 words
The method for fabricating a surface acoustic wave interdigital transducer defined in claim 1 wherein said thinning factor THIN is a value that provides maximum interdigital transducer loading reduction and not more than acceptable preselected response function degradation.
Claim 4
Dependent Claim
75 words
A surface acoustic wave interdigital transducer having a response function H o '(N), said response function H o '(N) being a preselected idealized response function H o (N) scaled by a thinning factor THIN, said thinning factor THIN being a positive non-zero number with a maximum value of less than unity, said transducer comprising opposed sets of overlapping electrodes, said electrodes being in appropriate quantity and arrangement to synthesize said response function H o '(N).
Claim 5
Dependent Claim
75 words
A surface acoustic wave interdigital transducer having a response function H o '(N), said response function H o '(N) being a preselected idealized response function H o (N) scaled by a thinning factor THIN, said thinning factor THIN being a positive non-zero number with a maximum value of less than unity, said transducer comprising opposed sets of overlapping electrodes, said electrodes being in appropriate quantity and arrangement to synthesize said response function H o '(N).
Claim 6
Dependent Claim
36 words
A surface acoustic wave interdigital transducer as defined in claim 3 wherein said thinning factor THIN is a value that provides maximum interdigital transducer loading reduction and not more than acceptable preselected idealized response function degradation.
References Cited (Backward Citations)
US3946342A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |