Patent EP0401839A2 successfully refreshed from Google Patents.
EP0401839A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
ceramic band-pass filter
Assignee: Pulse Finland Oy
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Filing: 1990-06-07
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Granted: —
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Expires: 2010-06-07
Abstract
Abstract A dielectric filter is formed from a block (10) of ceramic material with holes (16, 17, 18, 19) extending from a top surface (11) toward a bottom surface (12). At least the bottom (12), both ends (13) and one side surface (14) are coated with conductive material. Also, the interior surfaces of the holes (16, 17, 18, 19) are coated with conductive material to form transmission line resonators. The uncoated side surface has an electrode pattern which allows coupling to the filter and between resonators of the filter. The elevation of the electrodes on the side surface between the top (11) and bottom (12) determines whether the coupling is capacitive, mixed inductive and capacitive, or inductive.
Inventors
- 👤 Aimo Turunen
- 👤 Pauli Näppä
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 19:00
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205; H01P1/2056
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
187 words
A filter comprising: a body of dielectric material having (a) first and second surfaces on opposite sides of the body, (b) at least two side surfaces generally orthogonal to the first and second surfaces and connecting the edges of the first and second surfaces to each other, and (c) two end surfaces connecting the ends of the first, second and side surfaces to each other; said body defining at least one hole with an interior surface which extends into said body from said first surface toward said second surface; a conductive layer covering major portions of the second surface, one side surface, both end surfaces, and the interior surface of said hole so as to form at least one transmission line resonator; and an electrically-conductive electrode pattern means located on the other side surface for providing electrical signal coupling to and from the transmission line resonator, the coupling varying from (a) capacitive to (b) mixed capacitive and inductive to (c) inductive, depending on the relative location of the pattern means on the side surface between areas adjacent the first surface to areas adjacent the second surface, respectively.
Claim 2
Dependent Claim
187 words
A filter comprising: a body of dielectric material having (a) first and second surfaces on opposite sides of the body, (b) at least two side surfaces generally orthogonal to the first and second surfaces and connecting the edges of the first and second surfaces to each other, and (c) two end surfaces connecting the ends of the first, second and side surfaces to each other; said body defining at least one hole with an interior surface which extends into said body from said first surface toward said second surface; a conductive layer covering major portions of the second surface, one side surface, both end surfaces, and the interior surface of said hole so as to form at least one transmission line resonator; and an electrically-conductive electrode pattern means located on the other side surface for providing electrical signal coupling to and from the transmission line resonator, the coupling varying from (a) capacitive to (b) mixed capacitive and inductive to (c) inductive, depending on the relative location of the pattern means on the side surface between areas adjacent the first surface to areas adjacent the second surface, respectively.
Claim 3
Dependent Claim
51 words
A filter as claimed in claim 1 wherein there are at least two holes in the body forming at least two resonators, said pattern means extending along the other side surface from the vicinity of one of the resonators to the vicinity of another and providing electrical coupling between the resonators.
Claim 4
Dependent Claim
64 words
A filter as claimed in claim 2 further including an input lead connected to said pattern means in the vicinity of one resonator, and an output lead connected to said pattern means in the vicinity of another resonator so as to couple a signal into said filter on said input lead and to couple the signal out of said filter on said output lead.
Claim 5
Dependent Claim
49 words
A filter as claimed in claim 1 further including an electrically-conductive plate spaced from said other side surface by a certain gap and being electrically connected to the conductive layer on the other surfaces of said body, said conductive plate at least in part covering said other side surface.
Claim 6
Dependent Claim
40 words
The filter as claimed in claim 4, wherein the conductive plate is formed by a box-like shaped metal cover located over the other side surface so as to leave an air gap between the other side surface and the cover.
Claim 7
Dependent Claim
32 words
The filter as claimed in claim 4, wherein said air gap is filled with an insulating material and said conductive. plate is formed by a metal film located on the insulating layer.
Claim 8
Dependent Claim
37 words
The filter as claimed in claim 5, wherein the distance of cover from the other side surface of body is adjustable to change the size of the air gap, whereby the bandwidth of the filter is adjusted.
Claim 9
Dependent Claim
24 words
The filter as claimed in claim 6, wherein the bandwidth of the filter depends, in part, on the dielectric constant of the insulating material.
Claim 10
Dependent Claim
22 words
The filter as claimed in claim 6, wherein the bandwidth of the filter depends, in part, on the thickness of insulating material.
Claim 11
Dependent Claim
13 words
The filter as claimed in claim 6, wherein the insulating material is Teflon®.
Claim 12
Dependent Claim
56 words
The filter as claimed in claim 5, wherein the cover has an inner surface that forms a cavity in which the body is retained, said cavity having shoulders projecting from the inner surface that engage the body to keep the inner surface of cover at the determined distance from the other side surface of the body.
Claim 13
Dependent Claim
77 words
The filter as claimed in claim 2, wherein there are four resonators, and further including a coupling electrode pattern located on said other side surface for coupling said resonators to create a phase cancellation with signals within the body so as to form at least one imaginary zero positioned so that the shape of the pass band of the filter is substantially equivalent to that of a band-pass filter with six resonators, but without an imaginary zero.
Claim 14
Dependent Claim
49 words
The filter as claimed in claim 4 wherein the insulating material is a printed circuit board, the filter body being mounted on the board with the other side surface toward the board, and the surface of the printed circuit board opposite the body being covered with the conductive plate.
Claim 15
Dependent Claim
132 words
A band-pass filter comprising: a body of dielectric material having first and second surfaces on opposite sides of the body from each other, end surfaces and side surfaces; said body defining at least two holes extending from the first surface toward the second surface; a conductive coating on said second, end and one side surfaces, as well as the interior surfaces of the holes, to form at least two transmission line resonators; an insulating plate against the other side surface of the body; a conductive electrode pattern on the insulating plate, the electrode pattern providing coupling between the at least two resonators, said coupling being capacitive, mixed capacitive-inductive, and inductive depending on whether the pattern is near the first surface, between the first and second surfaces or near the second surface, respectively.
Claim 16
Dependent Claim
132 words
A band-pass filter comprising: a body of dielectric material having first and second surfaces on opposite sides of the body from each other, end surfaces and side surfaces; said body defining at least two holes extending from the first surface toward the second surface; a conductive coating on said second, end and one side surfaces, as well as the interior surfaces of the holes, to form at least two transmission line resonators; an insulating plate against the other side surface of the body; a conductive electrode pattern on the insulating plate, the electrode pattern providing coupling between the at least two resonators, said coupling being capacitive, mixed capacitive-inductive, and inductive depending on whether the pattern is near the first surface, between the first and second surfaces or near the second surface, respectively.
Claim 17
Dependent Claim
25 words
The filter as claimed in claim 14, wherein the electrode patterns are on that surface of said insulating plate against which the body is located.
Claim 18
Dependent Claim
30 words
The filter as claimed in claim 15, wherein the insulating plate is a multi-layer printed circuit board and the electrode patterns are in a conductive layer inside the multi-layer board.
Claim 19
Dependent Claim
50 words
The filter as claimed in claim 15, wherein, on the opposite side of the insulating plate from the body, at least in an area the size of the other side surface of the body, there is an electrically conductive plating that is electrically coupled to the conductive coating of body.
Claim 20
Dependent Claim
18 words
The filter as claimed in claim 14, wherein the body is fastened to the insulating plate by gluing.
Claim 21
Dependent Claim
18 words
The filter as claimed in claim 14, wherein the body is fastened to the insulating plate by soldering.
Claim 22
Dependent Claim
23 words
The filter as claimed in claim 14, wherein the body is mounted in a bracket which has been fastened to the insulating plate.
Claim 23
Dependent Claim
26 words
The filter as claimed in claims 1 or 14 wherein the first surface is covered with the conductive layer, except for an area around the hole.
Claim 24
Dependent Claim
61 words
A filter as claimed in claims 1 or 14 wherein the electrode pattern includes a conductive strip connected to the conductive coating and located along at least one edge of the other side surface near one of the first and second surfaces, removal of a portion of said strip adjacent the resonator being effective to change the frequency of the resonator.
Claim 25
Dependent Claim
26 words
A filter as claimed in claim 21 wherein the first surface of the body is coated with conductive material, except for a portion surrounding the hole.
Claim 26
Dependent Claim
34 words
A filter as claimed in claim 1 or 14 wherein removal of a portion of the dielectric material on the first surface adjacent a resonator is effective to alter the frequency of the resonator.
Claim 27
Dependent Claim
178 words
A duplexer filter for a radio having an antenna, a transmitter and a receiver, comprising: first and second blocks of dielectric material, each block having first and second surfaces on opposite sides from each other, end surfaces and side surfaces; each block defining at least one hole extending from the first surface to the second surface; a conductive coating over the second surface, end surfaces and one side surface, as well as over the interior of the hole of each block, so as to form at least one transmission line resonator in each block; conductive electrode patterns on the other side surface of each body for coupling to and from the resonator in each block, the coupling varying from capacitive, to mixed capacitive-inductive, to inductive as the pattern is located respectively on the other side surface near the first surface to between the first and second surfaces, to near the second surface; and connecting means for connecting the first block between the transmitter and the antenna, and for connecting the second block between the receiver and the antenna.
Claim 28
Dependent Claim
178 words
A duplexer filter for a radio having an antenna, a transmitter and a receiver, comprising: first and second blocks of dielectric material, each block having first and second surfaces on opposite sides from each other, end surfaces and side surfaces; each block defining at least one hole extending from the first surface to the second surface; a conductive coating over the second surface, end surfaces and one side surface, as well as over the interior of the hole of each block, so as to form at least one transmission line resonator in each block; conductive electrode patterns on the other side surface of each body for coupling to and from the resonator in each block, the coupling varying from capacitive, to mixed capacitive-inductive, to inductive as the pattern is located respectively on the other side surface near the first surface to between the first and second surfaces, to near the second surface; and connecting means for connecting the first block between the transmitter and the antenna, and for connecting the second block between the receiver and the antenna.
Claim 29
Dependent Claim
24 words
A duplexer filter as claimed in claim 24 wherein the connecting means includes a portion of the electrode pattern on the other side surface.
Claim 30
Dependent Claim
30 words
A duplexer filter as claimed in claim 26 wherein the portion of the electrode pattern is an electrode strip one-quarter wavelength of the resonant frequency of the resonator in length.
Claim 31
Dependent Claim
19 words
A duplexer filter as claimed in claim 26 wherein the portion of the electrode pattern forms a reactive component.
Claim 32
Dependent Claim
30 words
A duplexer filter as claimed in claim 25 wherein the electrode pattern for one of the blocks forms the block into a band-pass filter with at least one imaginary zero.
Claim 33
Dependent Claim
24 words
A duplexer filter as claimed in claim 25 wherein the electrode pattern for one of the blocks forms the block into a band-stop filter.
Claim 34
Dependent Claim
57 words
A duplexer filter as claimed in claim 24 wherein one of the first and second blocks has four holes and an electrode pattern that creates a four resonator band-pass filter with imaginary zeros at both sides of the pass-band, and the other block has three holes and an electrode pattern that creates a three resonator band-stop filter.
Claim 35
Dependent Claim
154 words
A filter comprising: first and second blocks of dielectric material, each block having first and second surfaces on opposite sides from each other, end surfaces and side surfaces; each block defining one hole extending from the first surface to the second surface; a conductive coating over the second surface, end surfaces and one side surface, as well as over the interior of the hole of each block, so as to form one transmission line resonator in each block; conductive electrode patterns on the other side surface of each block for coupling to and from the resonator in each block, the coupling varying from capacitive, to mixed capacitive-inductive, to inductive as the pattern is located respectively on the other side surface near the first surface, to between the first and second surfaces, to near the second surface; and connecting means for connecting the first block to the second block between the receiver and the antenna.
Claim 36
Dependent Claim
154 words
A filter comprising: first and second blocks of dielectric material, each block having first and second surfaces on opposite sides from each other, end surfaces and side surfaces; each block defining one hole extending from the first surface to the second surface; a conductive coating over the second surface, end surfaces and one side surface, as well as over the interior of the hole of each block, so as to form one transmission line resonator in each block; conductive electrode patterns on the other side surface of each block for coupling to and from the resonator in each block, the coupling varying from capacitive, to mixed capacitive-inductive, to inductive as the pattern is located respectively on the other side surface near the first surface, to between the first and second surfaces, to near the second surface; and connecting means for connecting the first block to the second block between the receiver and the antenna.
References Cited (Backward Citations)
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