US3866154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband unidirectional surface wave transducer
Assignee: Westinghouse Electric Corp
•
Filing: 1973-12-03
•
Granted: 1975-02-11
•
Expires: 1993-12-03
Abstract
Abstract The disclosure relates to a novel broadband surface wave acoustic transducer having unidirectional transduction characteristics and to surface wave acoustic devices employing the broadband unidirectional transducer. In the preferred embodiment, the transducer comprises an interdigital electrode arrangement having an electrically conductive common strip meandering through the interdigital spaces of the electrode arrangement. The interdigitally arranged electrodes are spaced in accordance with a repeating series (n + 1/4) lambda , (n + 3/4) lambda , (n + 1/4) lambda , (n + 3/4) lambda . . . , where n is an integer and lambda is an acoustic wavelength. The meandering strip provides a common terminal for the interdigital electrodes so that signals 90* out of phase may be applied between the electrodes and the common terminal.
Inventors
- 👤 Robert A Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:38
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14502; H03H9/14508
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
176 words
A surface wave transducer comprising: a substrate; a first plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; a second plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; said first plurality of members extending intermediate at least some of said second plurality of members in spaced, generally parallel and coplanar relation thereto; and, a common terminal for each of said first and second plurality of members, said common terminal comprising a strip of electrically conductive material spaced from and meandering through the spaces between said first and second plurality of members, the center-to-center spacing between adjacent members of said first plurality of members and between adjacent members of said second plurality of members being substantially equal to an odd multiple of acoustic wavelength of the substrate material, and each of said first plurality of members extending intermediate said second plurality of members at locations displaced approximately one quarter an acoustic wavelength from a location disposed centrally of adjacent of the members of said second plurality of members.
Claim 2
Dependent Claim
176 words
A surface wave transducer comprising: a substrate; a first plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; a second plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; said first plurality of members extending intermediate at least some of said second plurality of members in spaced, generally parallel and coplanar relation thereto; and, a common terminal for each of said first and second plurality of members, said common terminal comprising a strip of electrically conductive material spaced from and meandering through the spaces between said first and second plurality of members, the center-to-center spacing between adjacent members of said first plurality of members and between adjacent members of said second plurality of members being substantially equal to an odd multiple of acoustic wavelength of the substrate material, and each of said first plurality of members extending intermediate said second plurality of members at locations displaced approximately one quarter an acoustic wavelength from a location disposed centrally of adjacent of the members of said second plurality of members.
Claim 3
Dependent Claim
24 words
The transducer of claim 1 wherein said strip of conductive material varies in width to accommodate differences in spacing between adjacent of said members.
Claim 4
Dependent Claim
139 words
A surface wave transducer comprising: a substrate; a first plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; a second plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; said first plurality of members extending intermediate at least some of said second plurality of members in spaced, generally parallel and coplanar relation thereto; and, a common terminal for each of said first and second plurality of members, said common terminal comprising a strip of electrically conductive material spaced from and meandering through the spaces between said first and second plurality of members, each of said first plurality of members extending intermediate said second plurality of members at locations displaced approximately one quarter an acoustic wavelength from a location disposed centrally of adjacent of the members of said second plurality of members.
Claim 5
Dependent Claim
139 words
A surface wave transducer comprising: a substrate; a first plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; a second plurality of spaced, generally parallel, interconnected, electrically conductive members carried by said substrate; said first plurality of members extending intermediate at least some of said second plurality of members in spaced, generally parallel and coplanar relation thereto; and, a common terminal for each of said first and second plurality of members, said common terminal comprising a strip of electrically conductive material spaced from and meandering through the spaces between said first and second plurality of members, each of said first plurality of members extending intermediate said second plurality of members at locations displaced approximately one quarter an acoustic wavelength from a location disposed centrally of adjacent of the members of said second plurality of members.
Claim 6
Dependent Claim
24 words
The transducer of claim 3 wherein said strip of conductive material varies in width to accommodate differences in spacing between adjacent of said members.
Claim 7
Dependent Claim
100 words
A broadband unidirectional surface wave transducer comprising: two interdigital electrodes formed on an acoustic wave material and having interdigital electrode spacing defined by a repeating series (n + 1/4 ) lambda , (n + 3/4 ) lambda , (n + 1/4 ) lambda , (n + 3/4 ) lambda , . . . where n is an integer and lambda is an acoustic wavelength of said acoustic wave material; and, an electrically conductive strip spaced from and meandering through the interdigital spaces between said interdigital electrodes, said conductive strip forming a common terminal for each of the two interdigital electrodes.
Claim 8
Dependent Claim
100 words
A broadband unidirectional surface wave transducer comprising: two interdigital electrodes formed on an acoustic wave material and having interdigital electrode spacing defined by a repeating series (n + 1/4 ) lambda , (n + 3/4 ) lambda , (n + 1/4 ) lambda , (n + 3/4 ) lambda , . . . where n is an integer and lambda is an acoustic wavelength of said acoustic wave material; and, an electrically conductive strip spaced from and meandering through the interdigital spaces between said interdigital electrodes, said conductive strip forming a common terminal for each of the two interdigital electrodes.
Claim 9
Dependent Claim
25 words
The transducer of claim 5 wherein said conductive strip varies in width to provide substantially equally spacing between said conductive strip and said interdigital electrodes.
Claim 10
Dependent Claim
12 words
The transducer of claim 6 wherein the acoustic wave material is quartz.
Claim 11
Dependent Claim
11 words
The transducer of claim 6 wherein the integer n is one.
Claim 12
Dependent Claim
11 words
The transducer of claim 5 wherein the acoustic material is quartz.
Claim 13
Dependent Claim
11 words
The transducer of claim 5 wherein the integer n is one.
References Cited (Backward Citations)
US3675052A
Cited
US3800248A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |