US3743978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated ferrite rf filters
Assignee: Individual
•
Filing: 1970-11-09
•
Granted: 1973-07-03
•
Expires: 1990-11-09
Abstract
Abstract In a low pass RF filter, a coating of barium titanate is applied to a ferrite substrate. In one embodiment, the RF filter is an extruded tube of ferrite coated with barium titanate. The tube is used as an RF filter for a connector pin. In another embodiment, a thin strip of ferrite is coated with barium titanate. This forms a filter strip for use on circuit boards or for use as a high capacity lossy power bus.
Inventors
- 👤 W Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:33
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/66; H01R13/719; H01R13/7197; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; H01P; H01P1/00; H01P1/20; H01P1/215; H03; H03H; H03H1/00; H03H1/0007
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
13 words
The filter recited in claim 1 wherein said substrate is a semi-conducting ceramic.
Claim 2
Dependent Claim
14 words
The filter recited in claim 2 wherein the semi-conducting ceramic is doped barium titanate.
Claim 3
Dependent Claim
13 words
The filter recited in claim 1 wherein said dielectric is undoped barium titanate.
Claim 4
Dependent Claim
15 words
The filter recited in claim 1 wherein the layer of dielectric material is coated thereon.
Claim 5
Dependent Claim
21 words
The filter rEcited in claim 1 wherein the tubular member is a metallic plating over the inner surface of the sleeve.
Claim 6
Dependent Claim
20 words
The filter recited in claim 5 wherein the outer conductive layer is metallic plating over said layer of dielectric material.
Claim 7
Dependent Claim
95 words
A unitary low pass filter strip for mounting on a circuit board provided with a ground plane conductor comprising, a substrate in the form of a flat strip of semiconductive material, a conductive metal plating on one surface of the substrate, a coating of dielectric material on the opposite surface of the substrate, and a conductive metal plating on the outer surface of the dielectric coating, one of said platings being connected to one terminal of a low frequency source and load, and the other plating being in conductive engagement with the ground plane conductor.
Claim 8
Dependent Claim
13 words
The filter of claim 8 in which the substrate is a semiconductive ceramic.
Claim 9
Dependent Claim
13 words
The filter of claim 8 in which the substrate is doped barium titanate.
Claim 10
Dependent Claim
13 words
The filter of claim 8 in which the dielectric is undoped barium titanate.
Claim 11
Dependent Claim
97 words
A unitary low pass filter element for mounting on a conductor of a low frequency transmission line to attenuate high frequencies thereon comprising, a conductive tubular member for receiving a conductor therein, a substrate of ferrite in the form of a sleeve secured to the outer surface of the tubular member, in intimate engagement therewith, a layer of dilectric material covering the outer surface of the sleeve in direct intimate contact therewith, and an outer conductive layer disposed about and secured to the dielectric material substantially the length thereof for connecting the unitary filter element to ground.
Claim 12
Dependent Claim
13 words
The filter recited in claim 12 wherein said dielectric is undoped barium titanate.
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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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |