US3870975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface wave transducer with reduced reflection coefficient
Assignee: BAE Systems Aerospace Inc
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Filing: 1974-03-22
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Granted: 1975-03-11
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Expires: 1994-03-22
Abstract
Abstract Disclosed is an acoustic surface wave transducer having three conductive fingers per acoustic wavelength. Surface waves are excited by applying electrical signals across a pair of terminals. One terminal is connected to every third conductive finger in the transducer and the other terminal to the remaining conductive fingers.
Inventors
- 👤 Carmine F Vasile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:55
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14544; H03H9/14552; H03H9/02535; H03H9/02818; H03H9/02842; H03H9/14555
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
157 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface waves on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array; whereby, when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes An acoustic surface wave to propagate on said piezoelectric substrate.
Claim 2
Dependent Claim
157 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface waves on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array; whereby, when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes An acoustic surface wave to propagate on said piezoelectric substrate.
Claim 3
Dependent Claim
157 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface waves on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array; whereby, when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes An acoustic surface wave to propagate on said piezoelectric substrate.
Claim 4
Dependent Claim
157 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface waves on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array; whereby, when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes An acoustic surface wave to propagate on said piezoelectric substrate.
Claim 5
Dependent Claim
49 words
An acoustic surface wave transducer as specified in claim 1 wherein said two conductive fingers in said second array which are between each pair of adjacent fingers in said first array have a center-to-center spacing of one-third of an acoustic wavelength at a selected frequency in said frequency band.
Claim 6
Dependent Claim
33 words
An acoustic surface wave transducer as specified in claim 1 wherein the center-to-center spacing between adjacent pairs of conductive fingers in said first array is tapered over the length of said first array.
Claim 7
Dependent Claim
152 words
An acoustic surface wave device comprising: a piezoelectric substrate, a first transducer responsive to electrical signals for launching acoustic surface waves in a selected frequency band and a second transducer responsive to said acoustic surface waves for developing output electrical signals, at least one of said transducers comprising: a first array of conductive fingers, disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array.
Claim 8
Dependent Claim
152 words
An acoustic surface wave device comprising: a piezoelectric substrate, a first transducer responsive to electrical signals for launching acoustic surface waves in a selected frequency band and a second transducer responsive to said acoustic surface waves for developing output electrical signals, at least one of said transducers comprising: a first array of conductive fingers, disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array; and second conductive means for connecting the fingers of said second array.
Claim 9
Dependent Claim
232 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface wave on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array, said two conductive fingers in said second array which are between each pair of adjacent fingers in said first array having a center-to-center spacing of one-third of an acoustic wavelength at a selected frequency in said frequency band and each of the fingers of said second array having with respect to the adjacent finger of said first array a center-to-center spacing of one-third of an acoustic wavelength at a selected frequency in said frequency band; and second conductive means for connecting the fingers of said second array; whereby when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes an acoustic surface wave to propogate on said piezoelectric substrate.
Claim 10
Dependent Claim
232 words
An acoustic surface wave transducer for coupling electrical signals in a selected frequency band to acoustic surface wave on a piezoelectric substrate, comprising: a first array of conductive fingers disposed on one surface of said piezoelectric substrate and having a center-to-center spacing between adjacent pairs of conductive fingers of one acoustic wavelength at a selected frequency within said selected frequency band; first conductive means for electrically connecting the fingers of said first array; a second array of conductive fingers disposed on the same surface of said piezoelectric substrate and interleaved with said first array such that there are two conductive fingers in said second array between each pair of adjacent fingers in said first array, said two conductive fingers in said second array which are between each pair of adjacent fingers in said first array having a center-to-center spacing of one-third of an acoustic wavelength at a selected frequency in said frequency band and each of the fingers of said second array having with respect to the adjacent finger of said first array a center-to-center spacing of one-third of an acoustic wavelength at a selected frequency in said frequency band; and second conductive means for connecting the fingers of said second array; whereby when electrical signals in said selected frequency band are applied across said first and second conductive means, it causes an acoustic surface wave to propogate on said piezoelectric substrate.
References Cited (Backward Citations)
US3792381A
Cited
US3803520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |