JPH07170101A - Dielectric filter - Google Patents

Abstract

PURPOSE:To obtain an inexpensive small sized dielectric filter by eliminating the need for a metallic case so as to reduce the manufacturing man-hours. CONSTITUTION:Resonator holes 2a, 2b, 2c each with an inner conductor 3 formed in a dielectric block 1, and a coupling pin 20 in capacitance couple with the inner conductor 3 is inserted into the resonator holes in a dielectric resonator 10 with an outer conductor 4 formed on the outside of the dielectric block 1. In the dielectric filter 1 formed as above, a projection 5 with a ground conductor formed is formed to one open side of the resonator hole to which the coupling pin 20 is inserted, and a dollar of a resin section 20a of the coupling pin 2 is formed so as to be projected from the tip of the projection by the presence of the projection 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a car telephone,
The present invention relates to a dielectric filter used in mobile communication devices such as mobile phones.

[0002]

2. Description of the Related Art FIG. 6 shows the structure of a conventional general dielectric filter using a dielectric block. In the following perspective views, the dot-filled portion shows the visible portion (conductor non-forming portion) of the dielectric block.

As shown in FIG. 6, a conventional dielectric filter has a resonator hole 2 corresponding to an input / output stage of a dielectric resonator 10.
The connecting pins 20 and 20 are inserted into a and 2c, respectively, covered with a metal case 30, and soldered to the outer conductor 4 of the dielectric block 1 so as to be integrated as a whole.

The dielectric resonator 10 has, for example, three resonator holes 2a, 2b, 2c formed through a pair of opposed faces 1a, 1b of a substantially rectangular parallelepiped dielectric block 1, and each of them has three resonator holes 2a, 2b, 2c. Inner conductors 3, 3, 3 are formed on the inner peripheral surfaces of the resonator holes 2a, 2b, 2c, and an outer conductor 4 is formed on the outer surface of the dielectric block 1. Each of the inner conductors 3, 3, 3 has a portion where the inner conductor 3 is not formed (hereinafter referred to as an inner conductor) in the vicinity of one opening surface 1a (hereinafter, referred to as an open side end surface) of the resonator holes 2a, 2b, 2c. The non-formed portion) is provided, and the outer conductor 4
And the outer conductor 4 is opened (separated) on the other opening surface 1b.
Is short-circuited (conducted).

This dielectric resonator 10 has each resonator hole 2
It is composed of three-stage resonators formed for each of a, 2b, and 2c, and each resonator has an inner conductor non-contact between the inner conductor 3 and the outer conductor 4 in each resonator hole 2a, 2b, 2c. It is coupled by the stray capacitance by the forming part.

The coupling pin 20 comprises a resin portion 20a and a metal input / output terminal 20b penetrating the resin portion 20a. The resin portion 20a is inserted from the open end face 1a side into the resonator holes 2a and 2c corresponding to the input / output stages. It is then fixed by binding. The resin portion 20a is provided between the input / output terminal 20b of the coupling pin 20 and the inner conductors 3 in the resonator holes 2a and 2c corresponding to the input / output stage.
An external coupling capacitance is formed by

The metal case 30 holds the dielectric resonator 10 and the coupling pin 20, and is attached so as to cover the open end surface 1a of the dielectric block 1.

When this dielectric filter is mounted on a board, the input / output terminals 20b, 20b of the coupling pins 20, 20 are soldered to the input / output pattern formed on the board, and the protruding portions 30a, 30a of the metal case are provided. 30a and 30a are mounted by soldering to a ground pattern formed on the substrate.

[0009]

However, in the above-mentioned conventional dielectric filter, a metal case is required to serve as the ground of the filter, hold the dielectric resonator and the coupling pin, and integrate them as a whole. It is necessary to assemble and solder this metal case. Therefore, there is a problem that miniaturization is difficult, the cost of parts is high, the number of manufacturing steps is large, and the manufacturing cost is high.

Therefore, an object of the present invention is to solve the above problems of the conventional dielectric filter, reduce the number of parts, reduce the number of manufacturing steps, and reduce the cost and reduce the size of the dielectric. To provide a body filter.

[0011]

In order to achieve the above object, a dielectric filter according to claim 1 of the present invention has at least one resonator hole penetrating a pair of opposed surfaces of a dielectric block. A dielectric filter having an inner conductor formed on the inner peripheral surface of the resonator hole, an outer conductor formed on the outer surface of the dielectric block, and a coupling pin for capacitively coupling with the inner conductor. Is formed on one opening surface of the resonator hole, which is the insertion side of the above, in which a ground conductor that is electrically connected to the outer conductor is formed.

The dielectric filter according to claim 2 is
At least one resonator hole is provided through a pair of opposing surfaces of the dielectric block, an inner conductor is formed on an inner peripheral surface of the resonator hole, and an outer conductor is formed on an outer surface of the dielectric block, In a dielectric filter having a coupling pin that capacitively couples with the inner conductor, a recess in which the entire resin portion of the coupling pin is embedded is formed in one opening of a resonator hole into which the coupling pin is inserted. It is what

[0013]

According to the above construction, when the dielectric filter according to claim 1 is mounted on the substrate, the convex portion provided on one opening surface of the resonator hole is formed on the ground terminal or ground surface of the dielectric filter. Can be implemented as Further, when the dielectric filter according to claim 2 is mounted on the substrate, since the entire resin portion of the coupling pin is embedded in the recess provided in one opening of the resonator hole into which the coupling pin is inserted, The surface on the side where the coupling pin is inserted can be mounted on the substrate as a ground plane.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing the embodiments thereof. In the figure, parts that are the same as or equivalent to those of the conventional example, and those that have the same functions are assigned the same reference numerals and explanations thereof are omitted.

FIG. 1 shows the structure of a dielectric filter according to the first embodiment of the present invention. The dielectric filter of this embodiment is
As shown in FIGS. 1A and 1B, the dielectric resonator 10
The coupling pin 2 to the resonator holes 2a and 2c corresponding to the input and output stages of
It is configured by inserting 0 and 20 respectively.

The dielectric resonator 10 constituting the dielectric filter of this embodiment has six convex portions 5 around the open end face 1a which is one of the opening faces of the resonator holes 2a, 2b and 2c.
5, 5, 5, 5 and 5 are provided, and a ground conductor that is electrically connected to the outer conductor 4 is formed on the convex portion 5. Other configurations are the same as those described in FIG. 6 of the conventional example.

The coupling pin 20 comprises a resin portion 20a and a metal input / output terminal 20b penetrating the resin portion 20a, and the resin portion 20a is inserted from the open end face 1a side into the resonator holes 2a and 2c corresponding to the input / output stages. It is then fixed by binding.

Here, the convex portion 5 formed on the open side end surface 1a is molded integrally with the dielectric block 1, and the thickness in the direction perpendicular to the open side end surface 1a is the resin portion 20a of the coupling pin 20. It is larger than the thickness of the collar part. That is, the coupling pin 20 is inserted and fixed without the flange portion of the resin portion 20a protruding from the tip end surface of the convex portion 5 which is the mounting surface on the substrate.

When this dielectric filter is mounted on a substrate (not shown), the coupling pins 20 are inserted, and the open side end face 1a side provided with the convex portion is the substrate side, and the coupling pins 20, 20 are formed. The input / output terminals 20b and 20b are soldered to the input / output pattern formed on the substrate, and the convex portion 5 having the ground conductor is soldered to the ground pattern of the substrate for mounting.

As described above, in the dielectric filter according to the present embodiment, the metal case that serves as the ground of the filter and that holds the dielectric resonator and the coupling pin and integrates the whole is not required. The size can be reduced by that amount, the number of steps for assembling and soldering the metal case is unnecessary, and the component cost and the manufacturing cost can be reduced.

FIG. 2 shows the structure of the dielectric filter according to the second embodiment of the present invention. The dielectric resonator 10 constituting the dielectric filter of the present embodiment has a collar portion of the resin portion 20a of the coupling pin 20 in one opening of the resonator holes 2a, 2c into which the coupling pins 20, 20 are inserted. A recess having a substantially circular cross section that can be inserted is formed. The outer conductor 4 is formed on the inner surface of the recess 6, and the depth of the recess 6 in the direction perpendicular to the open end face 1a is equal to or larger than the thickness of the flange of the resin portion 20a of the coupling pin 20.

In the dielectric filter of this embodiment, the coupling pin 20 is inserted into the resonator holes 2a and 2c so that the entire resin portion 20a including the collar portion is embedded in the dielectric block. That is, the coupling pin 20 is inserted and fixed without the flange portion of the resin portion 20a protruding from the open end surface 1a.

When this dielectric filter is mounted on a substrate (not shown), the open side end face 1a side into which the coupling pin 20 is inserted is the substrate side, and the input / output terminals 20b and 20b of the coupling pins 20 and 20 are arranged. Is soldered to the input / output pattern formed on the substrate, and the open-side end surface 1a having the outer conductor 4 formed thereon is soldered to the ground pattern of the substrate for mounting.

Also in the structure of this embodiment, as in the first embodiment, it is possible to eliminate the need for a metal case, so that the size can be reduced and the parts cost and the manufacturing cost can be reduced.

In the first embodiment shown in FIG. 1, six convex portions are formed in the peripheral portion of the end face on the open side. However, the present invention is not limited to this, and each resonator hole is sandwiched as shown in FIG. It is also possible to form two protrusions on both sides thereof, and as shown in FIG. 4, one protrusion is provided in the middle portion of the resonator hole in the central portion and two protrusions are provided outside the resonator holes on both sides, for a total of three protrusions. 5 may be formed, or one projection may be formed including the resonator hole formed at the center as shown in FIG. Further, in each of the above embodiments, at least one surface of the convex portion is formed continuously with the side surface of the dielectric block. However, the present invention is not limited to this, and the stability at the time of mounting on the substrate, the characteristics of the dielectric filter, and the like. In consideration of the above, it can be formed at a desired position on the surface of the insertion side of the coupling pin. Further, the shape of the convex portion is not limited to the rectangular shape in cross section, but may be another shape such as a columnar shape.

That is, when the dielectric resonator is mounted on the substrate, one is provided on one opening surface of the resonator hole on which the coupling pin is inserted so that the surface of the tip of the convex portion abuts the surface of the substrate. Alternatively, a plurality of convex portions may be formed.

In the second embodiment shown in FIG. 2, the stepped circular recess is formed in one opening of the resonator hole into which the coupling pin is inserted, but the recess is not limited to this. However, it may be formed in another shape such as a rectangular cross section.

In the first and second embodiments described above, the dielectric filter including the combline type three-stage resonator has been described. However, as shown in FIGS. 3 and 4, there are four dielectric filters in the dielectric block. It may be composed of four-stage resonators having individual resonator holes, or may be a combline type dielectric filter composed of one-stage, two-stage, and five-stage or more resonators. further,
The present invention can also be applied to an interdigital dielectric filter having three or more stages and an odd number of stages.

Further, the separation of the inner conductor and the outer conductor at the open side end face is also provided with the inner conductor non-forming portion in the present embodiment, but the invention is not limited to this, and the convex portion provided at the open side end face is not limited to this. An outer conductor non-formation part may be provided on one surface of the open-side end surface except for.

[0030]

As described above, according to the dielectric filter of the present invention, the convex portion formed on one opening surface of the resonator hole on the insertion side of the coupling pin or the insertion side of the coupling pin. The dielectric filter can be mounted on the substrate by using the opening surface of the resonator hole as the ground terminal and the ground surface of the dielectric filter. That is, the dielectric filter can be easily grounded on the substrate without using a metal case that serves as a ground for the filter and holds the dielectric resonator and the coupling pin to integrate them as a whole.

Therefore, according to the present invention, it is possible to reduce the number of housings such as a metal case, thereby reducing the component cost and the manufacturing cost, and it is possible to obtain an inexpensive and small dielectric filter.

[Brief description of drawings]

FIG. 1A is an exploded perspective view showing an external appearance of a dielectric filter according to a first embodiment of the present invention, and FIG. 1B is an external perspective view showing a state in which a coupling pin shown in FIG. Is.

FIG. 2 is an exploded perspective view showing an appearance of a dielectric filter according to a second embodiment of the present invention.

FIG. 3 is an external perspective view of a dielectric filter having two protrusions according to another embodiment of the present invention.

FIG. 4 is an external perspective view of a dielectric filter having three projections according to another embodiment of the present invention.

FIG. 5 is an external perspective view of a dielectric filter having one convex portion according to another embodiment of the present invention.

FIG. 6 is an exploded perspective view showing the appearance of a conventional dielectric filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric block 2, 2a, 2b, 2c Resonator hole 3 Inner conductor 4 Outer conductor 5 Convex portion 6 Recessed portion 10 Dielectric resonator 20 Coupling pin

Claims (2)

[Claims] 1. A dielectric block is provided with at least one resonator hole penetrating through a pair of opposing surfaces, an inner conductor is formed on an inner peripheral surface of the resonator hole, and an outer surface is formed on an outer surface of the dielectric block. In a dielectric filter including a coupling pin that forms a conductor and capacitively couples with the inner conductor, a ground conductor that is conductive with the outer conductor is provided on one opening surface of the resonator hole that is the insertion side of the coupling pin. A dielectric filter having a formed convex portion. 2. A dielectric block is provided with at least one resonator hole penetrating a pair of opposing surfaces, an inner conductor is formed on an inner peripheral surface of the resonator hole, and an outer conductor is formed on an outer surface of the dielectric block. In a dielectric filter having a coupling pin that forms a conductor and capacitively couples with the inner conductor, a recess in which the entire resin portion of the coupling pin is embedded is formed in one opening of a resonator hole into which the coupling pin is inserted. A dielectric filter characterized by being formed.