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US4806889A Expired / Lapsed US ⏱️ 0.0 years remaining

Ceramic filter

Assignee: TDK Corp
•
Filing: 1988-04-28
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Granted: 1989-02-21
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Expires: 2008-04-28
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Abstract

Abstract A dielectric ceramic body for use in a band-pass filter. The ceramic body has a plurality of through holes formed to extend transversely from one side surface to another side surface which is opposite to the one side surface and arranged in series along a longitudinal direction of the body. Slits are formed on one of the aforementioned two side surfaces between respective two holes. The slits have depths which increase toward end portions of the ceramic body.

Inventors

  • 👤 Fumihito Nakano
  • 👤 Kiyoshi Hagawa
  • 👤 Kenji Endo
  • 👤 Kohei Wada
  • 👤 Katsuya Jindou

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 03:38
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205; H01P1/2056

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 161 words
A dielectric ceramic body for a ceramic filter, said body being of a cuboidal configuration having first side surface and a second side surface which is opposite to said first side surface, a plurality of holes arranged in series along a length of said body to extend from said first side surface to said second side surface add opening at the opposite ends to said first and second side surfaces, a plurality of slits formed at one of said first and second side surfaces and located one between each two adjacent pair of said holes, a first conductive layer provided at least on one of said first and second surfaces, a second conductive layer provided on an interior wall of each hole, said slits having depths which change so that the depth of the slit closer to an end portion of the ceramic body is greater than the depth of the slit closer to a center portion of the ceramic body.
Claim 2
Dependent Claim 161 words
A dielectric ceramic body for a ceramic filter, said body being of a cuboidal configuration having first side surface and a second side surface which is opposite to said first side surface, a plurality of holes arranged in series along a length of said body to extend from said first side surface to said second side surface add opening at the opposite ends to said first and second side surfaces, a plurality of slits formed at one of said first and second side surfaces and located one between each two adjacent pair of said holes, a first conductive layer provided at least on one of said first and second surfaces, a second conductive layer provided on an interior wall of each hole, said slits having depths which change so that the depth of the slit closer to an end portion of the ceramic body is greater than the depth of the slit closer to a center portion of the ceramic body.
Claim 3
Dependent Claim 67 words
A dielectric ceramic body in accordance with claim 1 in which said body has opposite end portions, said first and second side surfaces extending between said end portions, at least a predetermined number of said slits counted from each end portion having depths which increase toward said end portion of the ceramic body so that bottom portions of the slits are laid substantially along a parabolic curve.
Claim 4
Dependent Claim 56 words
A dielectric ceramic body in accordance with claim 1 in which said body has opposite end portions, said first and second side surfaces extending between said end portions, said slits having depths which increase toward said end portion of the ceramic body so that bottom portions of the slits are laid substantially along an annular curve.
Claim 5
Dependent Claim 24 words
A dielectric ceramic body in accordance with claim 1 in which said slits are formed in said one of the first and second surfaces.
Claim 6
Dependent Claim 24 words
A dielectric ceramic body in accordance with claim 1 in which said slits are formed in the other of the first and second surfaces.
Claim 7
Dependent Claim 90 words
A dielectric ceramic body in accordance with claim 1 in which the number of the slits is five with two outermost slits having substantially the same depth B 1 , two slits which are adjacent to said outermost slits having substantially the same depth B 2 , the center slit having a depth B 3 , the depths B 1 , B 2 and B 3 being determined substantially in accordance with formulae B.sub.2 =k×B.sub.1, B.sub.3 =k×B.sub.2 where k is a proportional coefficient having a value between 0.65 and 0.95.
Claim 8
Dependent Claim 70 words
A dielectric ceramic body in accordance with claim 1 in which the number of the slits is three with two outer slits having substantially the same depth B 1 and the central slit having a depth B 2 which is determined with respect to the depth B 1 in accordance with a formula B 2 =k×B 1 where k is a proportional coefficient having a value between 0.65 and 0.95.
Claim 9
Dependent Claim 105 words
A dielectric ceramic body in accordance with claim 1 in which the number of slits is N and the depths of the slits are determined in accordance with formula B.sub.m (or B.sub.N-m)=k.sub.m ×B.sub.m-1 B m is the depth of the slits with the suffix m representing the order of the slit counted from one end of the body, m being a largest integer which does not exceed (N-1)/2, and k m is a proportional coefficient having a value between 0.65 and 0.95 in case where m is 2 and N-1 and a value between 0.8 and 1.0 in case where m is 3 to N-2.
Claim 10
Dependent Claim 23 words
A dielectric ceramic body in accordance with claim 1 in which all of said slits are coated with layers of a conductive material.
Claim 11
Dependent Claim 24 words
A dielectric ceramic body in accordance with claim 1 in which all of said slits are not coated with layers of a conductive material.
Claim 12
Dependent Claim 42 words
A dielectric ceramic body in accordance with claim 1 in which at least one of said slits is coated with a conductive material, said one slit being decreased in depth than a depth as determined for a slit having no conductive coating.
Claim 13
Dependent Claim 18 words
A dielectric ceramic body in accordance with claim 1 in which said holes are arranged with uniform spacings.
Claim 14
Dependent Claim 48 words
A dielectric ceramic body in accordance with claim 1 in which at least two adjacent holes are arranged with a smaller spacing than the other hole spacings, the slit between said two adjacent holes being decreased in depth than a depth as determined for a uniform hole spacing.
Claim 15
Dependent Claim 55 words
A dielectric ceramic body in accordance with claim 1 in which dielectric material is removed from said body at the other of the first and second side surfaces in an area encircled by a pair of transverse tangent lines drawn on the hole for holes which are not closest to an end of the body.
Claim 16
Dependent Claim 60 words
A dielectric ceramic body in accordance with claim 1 in which dielectric material is removed from said body at the other of the first and second side surfaces in an area outside of a transverse tangent line drawn on the hole which is closest to an end of the body at a side opposite to said end of the body.

References Cited (Backward Citations)

US3505618A Cited
US4255729A Cited
US4464640A Cited
US4431977A Cited
US4607242A Cited
JPS6143285A Cited
JPS6143287A Cited
US4733208A Cited
JPS638642A Cited
US4692726A Cited
US4745379A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-02-21 1992-08-22 1993-02-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-02-21 1996-08-22 1997-02-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-02-21 2000-08-22 2001-02-21 $7700.00 Window Closed / Lapsed

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