US3638146A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric ceramic filter
Assignee: Toko Inc
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Filing: 1969-09-24
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Granted: 1972-01-25
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Expires: 1989-09-24
Abstract
Abstract An improved piezoelectric ceramic filter for use in a frequency range above 1 MHz., which uses the thickness expansion or thickness shear mode of the vibration of a thin ceramic plate having opposed surface electrodes, and having conductor leads from the electrodes disposed at right angles. The body of the filter is a thin ceramic platelike member. A divided active electrode comprising a pair of electrode sectors each having a relatively straight marginal side is mounted on one surface of said body in a manner whereby the marginal straight sides are spaced slightly apart in parallel. A ground electrode is mounted in at least partial peripheral alignment with said active electrode, but on the opposite surface of said body, and corresponds in area size and shape to at least a major portion of that of said active electrode. The active and ground electrodes have a common overlap area which is not in excess of an area whose linear dimension in one direction is one-half that of the other direction, and said area is preferably of a semicircular shape.
Inventors
- 👤 Tetsuo Takaku
- 👤 Meiji Miyashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:53
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/56; H03H9/562
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
186 words
An improved piezoelectric ceramic filter for use in a frequency range above 1 MHz., and adapted to utilize the thickness expansion or thickness shear mode of the vibration of a thin ceramic plate having opposed surface electrodes, with conductor leads of the electrodes disposed at right angles, said filter comprising in combination: a. a thin ceramic platelike body having opposite generally flat surfaces; b. a divided active electrode comprising a pair of active electrode sectors each having arcuate outer peripheries encompassing at least a quadrantlike area together with at least one relatively straight inner marginal side, and said sectors being mounted on one surface of said body with said electrode marginal straight sides spaced slightly apart in parallel; c. a ground electrode mounted in at least partial peripheral alignment with said active electrode, but on the opposite surface of said body, and corresponding in area size and shape to at least a major portion of that of said active electrode; and d. said active and ground electrodes facing each other through said ceramic body and having a common overlap area which is of generally semicircular form.
Claim 2
Dependent Claim
186 words
An improved piezoelectric ceramic filter for use in a frequency range above 1 MHz., and adapted to utilize the thickness expansion or thickness shear mode of the vibration of a thin ceramic plate having opposed surface electrodes, with conductor leads of the electrodes disposed at right angles, said filter comprising in combination: a. a thin ceramic platelike body having opposite generally flat surfaces; b. a divided active electrode comprising a pair of active electrode sectors each having arcuate outer peripheries encompassing at least a quadrantlike area together with at least one relatively straight inner marginal side, and said sectors being mounted on one surface of said body with said electrode marginal straight sides spaced slightly apart in parallel; c. a ground electrode mounted in at least partial peripheral alignment with said active electrode, but on the opposite surface of said body, and corresponding in area size and shape to at least a major portion of that of said active electrode; and d. said active and ground electrodes facing each other through said ceramic body and having a common overlap area which is of generally semicircular form.
Claim 3
Dependent Claim
27 words
An improved filter as defined in claim 1 whereiN the divided active electrode sectors are of generally semicircular shape, which together form a generally full circle shape.
Claim 4
Dependent Claim
36 words
An improved filter as defined in claim 2 wherein the ground electrode is of semicircular shape having a diametrical side marginal edge disposed at right angles to the corresponding straight marginal sides of said active electrode.
Claim 5
Dependent Claim
40 words
An improved filter as defined in claim 1 wherein the divided active electrode sectors are of generally right angular pie shape quadrants with a pair of adjacent edges spaced parallel apart from each other and together forming generally a semicircle.
Claim 6
Dependent Claim
28 words
An improved filter as defined in claim 4 wherein said ground electrode is also of semicircular shape and disposed to coincide with that formed by said active electrode.
Claim 7
Dependent Claim
18 words
An improved filter as defined in claim 4 wherein said ground electrode is of a generally circular shape.
Claim 8
Dependent Claim
19 words
An improved filter as defined in claim 4 wherein said ground electrode is of a uniform full circle form.
References Cited (Backward Citations)
FR748910A
Cited
US2596460A
Cited
US2829284A
Cited
US2859346A
Cited
US3018451A
Cited
US3401275A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |