JPH0624282B2 - Filter device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a structure of a filter device in which a plurality of coaxial resonance units are formed in a dielectric block, and more particularly to improvement of a structure in which the filter device is housed in a metal case.

[Prior Art] Japanese Utility Model Publication No. 58-178708 discloses a case housing structure of a dielectric filter device in which a plurality of coaxial resonance units are formed in a dielectric block. Here, the second
As shown in the figure, a dielectric block 1 constituting a coaxial resonance unit is housed between metal half cases 4 and 5 with metal leaf springs 2 and 3 interposed. Leaf springs 2, 3
Are interposed to electrically connect the outer conductors formed on the outer surface of the dielectric block 1 and the half cases 4 and 5, and are connected to the half cases 4 and 5 of the dielectric block 1. The fixing is performed by an adhesive filled in the leaf springs 2 and 3 excluding the portions having the repellency.

Reference numeral 6 denotes an input / output terminal, which is drawn out from the voltage open end face side of the dielectric block 1 and is drawn out through a hole 7 formed by combining the half cases 4 and 5.

[Problems to be Solved by the Invention] In the above-described conventional configuration, two metal half-cases 4 and 5 and leaf springs 2 and 3 are required. Therefore, the number of parts is considerably large, and the number of assembling steps is large. There was a problem in terms of mass productivity.

Therefore, an object of the present invention is to provide a filter device which has a small number of parts, is easy to assemble, and is therefore highly reliable and mass producible.

[Means for Solving Problems] A filter device according to the present invention includes a dielectric block having a plurality of through holes, an inner conductor formed on the inner surface of the through hole of the dielectric block, and an outer surface of the dielectric block. The formed outer conductor, an input / output terminal part of which is inserted into the through hole of the dielectric block and protrudes toward the voltage open end surface side, and is arranged around the input / output terminal in the through hole and near the voltage open end surface side. In the dielectric block, a plurality of coaxial resonance units are formed in the dielectric block, and a plurality of coaxial resonance units are coupled to the dielectric filter, and at least the dielectric block. Cover the open end of the voltage,
Further, a cutout portion for inserting the input / output terminal in a non-contact state is formed on the surface covering the voltage open end surface, and the distance between the surface covering the voltage open end surface and the voltage open end surface of the dielectric block is defined by the outer cylinder. It includes a prescribed metal case and a conductive bonding material for electrically connecting the outer conductor of the dielectric block to the metal case and mechanically fixing the metal case.

As described above, since the input / output terminal is inserted into the cutout portion in a non-contact state, the input / output terminal has a cross-sectional dimension smaller than the inner dimension of the cutout portion. Further, in order that the distance between the voltage open end surface of the dielectric block and the surface of the metal case that covers the dielectric block is defined by the outer cylinder,
The protrusion to the voltage open end face side has a size such that it contacts the voltage open end face at the edge of the through hole and contacts the surface covering the voltage open end face of the metal case at the edge of the cutout.

[Operation and Effect of the Invention] In the present invention, the dielectric filter is mechanically bonded to the integral metal case in which the cut-out portion for inserting the input / output terminal is formed on the surface covering the voltage open end surface by the conductive bonding material. Since it has a structure in which the outer conductor is electrically connected by the joining material, the number of parts is greatly reduced as compared with the conventional filter device shown in FIG.
Therefore, it is possible to assemble easily and inexpensively.

Further, according to the present invention, the outer cylinder arranged around the input / output terminal defines the distance between the surface of the metal case covering the voltage open end surface and the voltage open end surface of the dielectric block. It is easy to keep the product constant and obtain the product. Since resonance electromagnetic field energy exists in the space contacting the voltage open end face of the dielectric block, the insertion loss and the resonance frequency will fluctuate unless the above-mentioned interval is always kept constant. For example, such variations can be prevented. Further, since the outer cylinder is sandwiched and held between the metal case and the dielectric block, the outer cylinder and the input / output terminal do not fall out from the through hole of the dielectric block.

Description of Embodiments FIG. 1 shows a first embodiment of the present invention, in which a dielectric filter 11 is fixed in a metal case 12.

As shown in FIG. 3, the dielectric filter 11 has a plurality of through holes 22 and 23 formed in, for example, a titanium oxide ceramic dielectric block 21, and inner conductors 24 and 25 are formed on the inner surfaces of the through holes 22 and 23. The outer conductor 26 is formed on the outer surface of the other dielectric block 21, and the inner conductors 24, 25 and the outer conductor 26 are short-circuited by the short-circuit conductor 26a formed on one end surface of the dielectric block 21. , 25 and outer conductor 26
And a dielectric block portion interposed therebetween to form a pair of resonance units, and the dielectric block portion between the resonance units is a cavity as one means for taking a coupling between the resonance units. 27 is formed,
Further, an external circuit (not shown) and the resonance unit are electrostatically coupled by an input / output coupling capacitor.
It is a / 4 wavelength distributed constant type filter.

In FIG. 3, reference numeral 31 is an input terminal and 32 is an output terminal. Outer cylinders 33 and 34 made of a dielectric material are attached around the input / output terminals 31 and 32.
The capacitance based on 3, 34 constitutes the input / output coupling capacitor. The input / output terminals 31 and 32 have through holes 2
A part is inserted in 2, 23 and protrudes to the voltage open end face side. In addition, the outer cylinders 33, 34 have the through holes 22, 23.
A part is arranged inside, and a part projects to the voltage open end face side.

On the other hand, as shown in FIG. 4, the metal case 12 is made of a U-shaped plate-shaped metal member, and has a first surface 35 that covers the voltage open end surface of the dielectric filter 11 and a first surface 35. The second surface 36, 37 is bent from the surface 35 and covers the side surface of the dielectric filter 11. The first surface 35 covering the voltage open end surface has holes 35a, 3 as cutout portions.
5b is formed. The input / output terminals 31 and 32 have cross-sectional dimensions smaller than the inner dimensions of the holes 35a and 35b. Further, the protruding portions of the outer cylinders 33 and 34 toward the voltage release end surface side contact the voltage release end surface at the edge portions of the through holes 22 and 23, and the voltage release end surface of the metal case 12 at the edge portions of the holes 35a and 35b. Has a size that abuts the first surface 35 that covers the. Therefore, as shown in FIG. 4, when the dielectric filter 11 is inserted into the metal case 12, the input / output terminals 31 and 32 are pulled out from the holes 35a and 35b without coming into contact with the metal case 12, and the outside To reliably position the dielectric filter 11 with respect to the metal case 12 in a state where the distance between the voltage open end surface and the first surface 35 of the metal case 12 is kept constant by the protruding portions of the tubes 33 and 34. You can

On the other hand, slits 36a and 37a are formed on the second surfaces 36 and 37 of the metal case 12. Slit 36
a and 37a are provided for soldering the outer conductor 26 of the dielectric filter 11 and the second surfaces 36 and 37, respectively. In this embodiment, by utilizing the slits 36a and 37a, the outer conductor 26 of the dielectric filter 11 and the metal case 12 are joined by solder as a conductive joining material, and the outer conductor 26 is mechanically fixed and is joined together. And the metal case 12 is electrically connected. Note that as the conductive bonding material, any material such as conductive paste can be used in addition to solder. A side view of the fixed state is shown in FIG.

In the above-described embodiment, the dielectric filter 1 is formed only by using the metal case 12 formed by molding the plate-shaped metal member and the conductive bonding material.
Since the storage structure of No. 1 is configured, it can be seen that the number of parts can be greatly reduced and the assembly can be performed much more easily than the conventional filter structure shown in FIG.

Further, since the metal case 12 has the first surface 35 that covers the voltage open end surface side of the dielectric filter 11, the resonance electromagnetic field does not leak to the outside, and thus has an undesired influence on the external circuit. , On the contrary, it is not given. Further, unlike the conventional filter device shown in FIG. 2, it is not necessary to provide a space above the dielectric filter 1, so that the overall shape is considerably reduced.

Since the embodiment of FIG. 1 is to be inserted into the substrate in the vertical direction of FIG. 1, the metal case 12 has a board insertion tongue piece 38 in a direction orthogonal to the voltage open end surface of the dielectric filter 11. When the filter device is placed horizontally on the substrate, the tongue piece 3 for inserting the substrate is extended as shown in FIG.
9 may be bent and formed in a direction orthogonal to the input / output terminals 31 and 32.

Further, in the embodiment shown in FIG. 1, the metal case 12 having the first surface 35 covering the voltage open end surface and the second surfaces 36 and 37.
However, as shown in FIG. 7, a cylindrical metal case 42 formed by drawing may be used. In this case, the tubular metal case 42 has an opening at the top, and the dielectric filter 11 is inserted through the opening at the top. Further, on the bottom surface of the metal case 42, that is, the dielectric filter 11
On the surface that covers the voltage open end, there is also formed a cutout portion such as a hole for inserting the input / output terminal. Therefore, similarly to the embodiment shown in FIG. 1, by inserting the dielectric filter 11 into the metal case 42, the positioning of the input / output terminals can be achieved, and the filter device can be constructed with a small number of parts. Has been done. Also in the embodiment of FIG. 7, the metal case 42 is mechanically fixed to the dielectric filter 11 by a conductive bonding material such as solder or conductive paste, and electrically connected to the outer conductor 26 of the dielectric filter 11. It is connected to the.

Next, an embodiment in which an arbitrary number of dielectric filters are incorporated in the same metal case will be described. For example, the antenna duplexer is composed of a large number of dielectric resonators, capacitors, and coupling substrates, and the number of parts is essentially large, and as a result, the overall structure is considerably complicated. The following embodiments are intended to solve such a problem, and show structural examples for simplifying the filter device using a plurality of the integrated dielectric filters 11 shown in FIG.

In the embodiment shown in FIG. 8, two dielectric filters 11a and 11b are attached to the metal case 52. The metal case 52 has the same structure as the metal case 12 in the embodiment of FIG.
A cutout portion such as a hole through which an input / output terminal can be inserted is formed on a first surface that covers the voltage open ends of 1a and 11b.
In addition, the second surface 53 has a slit 53a for soldering.
Are formed. Similarly, a slit (not shown) for soldering is also formed on the surface 54 of FIG.

In the embodiment shown in FIG. 8, one dielectric filter 11a is used.
Is connected to the output side of the other dielectric filter 11b. Both dielectric filters 11a and 11b
The connection between them can be made by connecting the terminal 32a of one dielectric filter 11a and the terminal 31b of the other dielectric filter 11b with a conductive wire 56, as shown in FIG. 9, for example.

Alternatively, as shown in FIG. 10, the terminal 32a itself may be bent and directly soldered to the terminal 31b for connection. Further, as shown in FIG. 11, the terminals 31a, 31b, 32a, 32b are inserted into the wiring board 60 on the mounting side on which the conductive patterns 57 ... 59 are formed, and the terminals 32a and the terminals 32a are connected by the conductive pattern 58 on the board. 31b may be electrically connected. Similarly, the eleventh
Instead of the wiring board 60 on the mounting side shown in the figure, an electrode pattern is formed on the outside of the first surface that covers the voltage open end surface of the metal case 52 with substantially the same external dimensions as the first surface, similarly to the board 60. A substrate (not shown) is attached and terminals 32a are preliminarily attached.
And the terminal 31b may be electrically connected.

Two dielectric filters 11 as in the embodiment of FIG.
When it is necessary to lay down the dielectric filters 11a and 11b on the wiring board on the mounting side when a and 11b are used, as shown in FIG. 31b may be extended in a direction orthogonal to the input / output terminals 31a ... 31b.
... 32b has the conductive pattern 57 shown in FIG.
The connection tabs 62 ... 64 corresponding to 9 are attached to each tab 62.
The end of 64 may be inserted into the connection hole of the substrate.

FIG. 13 and FIG. 14 are perspective views showing a structural example in which the filter device configured as described above is placed horizontally and mounted on the wiring board on the mounting side. In FIG. 13, an opening for incorporation is formed in the substrate 142, and the filter device 144 is inserted into the opening, and the tongue pieces 146 and 146 are inserted.
It is fixed to the substrate 142 at 147. On the other hand, in the example of FIG. 14, the board 1 mounted outside the metal case 152
Connection tabs 155 ... 157 are fixed to the outer surface side of 53. The tips of the connection tabs 155 ... 157 are formed so that they can be inserted into the insertion holes formed in the wiring board on the mounting side (not shown), so that the input / output terminals of the dielectric resonators 11a and 11b are connected to the mounting board. Is configured to get.

In the example of FIG. 13, when the built-in opening is not formed in the substrate, the filter device is placed horizontally on the substrate and the input / output terminals of each dielectric resonator are directly connected to the conductive pattern on the substrate. Just connect.

The dielectric filter used in the present invention is not limited to the examples, and any known filter such as US Pat. No. 4,523,162 and US Pat.
7, JP-A-61-22003, and JP-A-60-2003.
It may be that disclosed in Japanese Patent Publication No. 254802.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention. FIG. 2 is a sectional view showing an example of a conventional filter device. FIG. 3 is a sectional view showing a dielectric filter used in the embodiment of FIG. FIG. 4 is a perspective view for explaining a process of assembling the embodiment shown in FIG. 1, and FIG. 5 is a side view of the embodiment shown in FIG. FIG. 6 is a perspective view showing a second embodiment of the present invention, and FIG. 7 is a perspective view explaining a third embodiment. FIG. 8 is a perspective view of an embodiment incorporating a plurality of dielectric filters, FIG. 9 is a front view showing a connection state of input / output terminals in the embodiment of FIG. 8, and FIG. 10 is a connection of input / output terminals. FIG. 11 is a schematic front view showing another example, FIG. 11 is a plan view for explaining still another example of the input / output terminal connection structure, and FIG. 12 is still another example of the input / output terminal connection structure. It is a perspective view shown. 13 and 14 are perspective views for explaining the connection structure with the substrate. In the figure, 11 is a dielectric filter, 12 is a metal case, 21 is a dielectric block, 22 and 23 are through holes, 2
4, 25 are inner conductors, 26 are outer conductors, 31 and 32 are input / output terminals, 35 is a first surface of a metal case, 36 and 37 are second surfaces of a metal case, and 35a and 35b are metal. The hole formed in a case is shown.

Claims (4)

[Claims] 1. A dielectric block (21) having a plurality of through holes (22, 23), and inner conductors (24, 2) formed on the inner surface of the through holes (22, 23) of the dielectric block (21).
5), the outer conductor (26) formed on the outer surface of the dielectric block (21), and the through hole (2) of the dielectric block (21).
2, 23), a part of which is inserted into the input / output terminals (31, 32) protruding toward the voltage open end surface side and the through holes (22, 2).
3) has an outer cylinder (33, 34) which is arranged around the input / output terminals (31, 32) and which is made of a dielectric material and partially protrudes on the voltage open end face side. A plurality of coaxial resonance units are configured, and a dielectric filter (1
1) and a surface (35) that covers at least the voltage open end surface of the dielectric block (21), and a surface (3 that covers the voltage open end surface.
5), a metal case (12) in which cutouts (35a, 35b) for inserting the input / output terminals (31, 32) are formed, and an outer conductor (26) of the dielectric block (21). And a conductive joint material for electrically connecting and mechanically fixing the metal case (12) to the metal case (12), and the input / output terminals (31, 32) include the cutout portion (35).
a, 35b) has a cross-sectional dimension smaller than the inner dimension, and the protruding portion of the outer cylinder (33, 34) toward the voltage open end face side is at the edge of the through hole (22, 23). The cutout portion (35) is brought into contact with the voltage open end face and
a, 35b) has a size that abuts the surface (35) covering the voltage open end surface of the metal case (12) at the edge of the metal case (12), whereby the input / output terminals (31, 32).
Does not contact the metal case (12) and covers the voltage open end face (35) and the dielectric block (2).
The outer cylinder (33, 34) is spaced from the voltage open end face of 1).
Filter device, defined by the protrusion of the. 2. A plurality of said dielectric filters (11a, 11b) are provided, and said plurality of dielectric filters (1).
The filter device according to claim 1, wherein 1a, 11b) are integrally fixed to one metal case (52). 3. The metal case (12, 52) has a first surface (35) covering the voltage open end surface of the dielectric block and a part of a side surface intersecting the voltage open end surface of the dielectric block. A filter device according to claim 1 or 2, comprising two surfaces (36, 37, 53, 54). 4. The dielectric block (21) has a plurality of side faces intersecting with a voltage open end face, and the metal case (1).
The second surface (36, 37, 53, 54) of (2, 52) is
The filter device according to claim 3, wherein the dielectric block (21) covers at least a part of a pair of opposite side surfaces of the plurality of side surfaces.