US3689784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband, high frequency, thin film piezoelectric transducers
Assignee: Westinghouse Electric Corp
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Filing: 1970-09-10
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Granted: 1972-09-05
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Expires: 1990-09-10
Abstract
Abstract Piezoelectric thin film transducers are provided in a form to match the impedance of a transmission line. The transducer structure includes a plurality of serially connected transducer elements on a single substrate provided by a first pattern of electrodes on the substrate, a single layer of piezoelectric material overlying the first electrode pattern and a second electrode pattern overlying the piezoelectric layer with selective connections between electrodes of the first and second patterns, such structure being directly amenable to fabrication by thin film technology. Such an arrangement provides greatly increased bandwidth characteristics and improved conversion efficiency.
Inventors
- 👤 John De Klerk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:59
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/0004; H03H9/02; H03H9/02228
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
151 words
Electroacoustic apparatus comprising: an electrical transmission line having a pair of conductors with a characteristic impedance therebetween; piezoelectric transducer means connected said transmission line and including a plurality of serially connected piezoelectric transducer elements on a single substrate having a combined impedance substantially matching that of said transmission line and a combined capacitance that is small compared with that of an individual one of said transducer elements; said plurality of serially connected piezoelectric transducer elements including a first pattern of a plurality of individual electrodes on said substrate, a single layer of piezoelectric material overlying said first electrode pattern, and a second pattern of a plurality of individual electrodes on said layer of piezoelectric material; and said electrodes of said first and second electrode patterns extending beyond the periphery of said layer of piezoelectric material with direct overlying contact therebetween for selective connections between electrodes of said first and second patterns.
Claim 2
Dependent Claim
151 words
Electroacoustic apparatus comprising: an electrical transmission line having a pair of conductors with a characteristic impedance therebetween; piezoelectric transducer means connected said transmission line and including a plurality of serially connected piezoelectric transducer elements on a single substrate having a combined impedance substantially matching that of said transmission line and a combined capacitance that is small compared with that of an individual one of said transducer elements; said plurality of serially connected piezoelectric transducer elements including a first pattern of a plurality of individual electrodes on said substrate, a single layer of piezoelectric material overlying said first electrode pattern, and a second pattern of a plurality of individual electrodes on said layer of piezoelectric material; and said electrodes of said first and second electrode patterns extending beyond the periphery of said layer of piezoelectric material with direct overlying contact therebetween for selective connections between electrodes of said first and second patterns.
Claim 3
Dependent Claim
95 words
The subject matter of claim 1 wherein: said first and second electrode patterns each comprise a plurality of generally strip-like parallel electrodes; said first pattern also includes a first major electrode tab joined with one of said strip-like electrodes of said pattern, said first major electrode tab being connected with one of said conductors of said transmission line; said second pattern also includes a second major electrode tab joined with one of said strip-like electrodes of said pattern, said second major electrode tab being connected with the other of said conductors of said transmission line.
Claim 4
Dependent Claim
63 words
The subject matter of claim 1 wherein: said substrate is an acoustic delay line material; between said first and second electrode patterns, in addition to said layer of piezoelectric material, is a continuous layer of a non-piezoelectric insulating material, thin compared with the thickness of said layer oF piezoelectric material, to ensure against any inadvertent electrical shorts through said layer of piezoelectric material.
Claim 5
Dependent Claim
149 words
Electroacoustic apparatus comprising: a substrate; a first electrode pattern on said substrate and designated as a bottom electrode pattern; a single layer of piezoelectric material overlying said bottom electrode pattern; a second electrode pattern on said layer of piezoelectric material on a surface thereof opposite said bottom electrode pattern and designated as a top electrode pattern; each of said electrode patterns comprising first and second spaced interdigitated comb-like electrode elements, said comb-like electrode elements each having a comb back positioned on said substrate beyond the periphery of said piezoelectric layer, said first comb-like electrode element of said top electrode pattern directly overlying said first comb-like electrode element of said bottom electrode pattern and said second comb-like electrode element of said top electrode pattern directly overlying said second comb-like electrode element of said bottom electrode pattern to permit creation of electric fields in said layer only parallel to said substrate.
Claim 6
Dependent Claim
149 words
Electroacoustic apparatus comprising: a substrate; a first electrode pattern on said substrate and designated as a bottom electrode pattern; a single layer of piezoelectric material overlying said bottom electrode pattern; a second electrode pattern on said layer of piezoelectric material on a surface thereof opposite said bottom electrode pattern and designated as a top electrode pattern; each of said electrode patterns comprising first and second spaced interdigitated comb-like electrode elements, said comb-like electrode elements each having a comb back positioned on said substrate beyond the periphery of said piezoelectric layer, said first comb-like electrode element of said top electrode pattern directly overlying said first comb-like electrode element of said bottom electrode pattern and said second comb-like electrode element of said top electrode pattern directly overlying said second comb-like electrode element of said bottom electrode pattern to permit creation of electric fields in said layer only parallel to said substrate.
Claim 7
Dependent Claim
154 words
Electroacoustic apparatus comprising: a substrate; a single layer of piezoelectric material supported on said substrate; first and second electrode patterns in contact with said piezoelectric layer, said first electrode pattern being located between said substrate and said piezoelectric layer and said second electrode pattern being located on a surface of said piezoelectric layer opposite said first electrode pattern, said first and second electrode patterns each comprising a plurality of spaced conductive elements with said conductive elements of said second pattern directly overlying said conductive elements of said first pattern; a resistive film serially interconnecting said conductive elements of said first pattern and serially interconnecting said conductive elements of said second pattern, said resistive film having a resistance greater than the resistance of the conductive elements of said first and second patterns; and means for applying a potential difference across the extremities of said resistive film to establish lateral electric fields in said piezoelectric layer.
Claim 8
Dependent Claim
154 words
Electroacoustic apparatus comprising: a substrate; a single layer of piezoelectric material supported on said substrate; first and second electrode patterns in contact with said piezoelectric layer, said first electrode pattern being located between said substrate and said piezoelectric layer and said second electrode pattern being located on a surface of said piezoelectric layer opposite said first electrode pattern, said first and second electrode patterns each comprising a plurality of spaced conductive elements with said conductive elements of said second pattern directly overlying said conductive elements of said first pattern; a resistive film serially interconnecting said conductive elements of said first pattern and serially interconnecting said conductive elements of said second pattern, said resistive film having a resistance greater than the resistance of the conductive elements of said first and second patterns; and means for applying a potential difference across the extremities of said resistive film to establish lateral electric fields in said piezoelectric layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |