JPH11103206A - Dielectric coaxial resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric coaxial resonator capable of reducing losses at an I/O electrode and easily executing fine adjustment for resonation frequency. SOLUTION: The resonator is provided with a dielectric block 3 formed by mixedly arranging plural dielectric parts having respectively different dielectric constants, a through hole 2 formed on the block 3, a ground electrode 5 formed on a prescribed outer periphery of the block 3, an inner peripheral electroe formed on the inner periphery of the through hole 2, and an I/O electrode 7 electrically connecting the inner peripheral electrode to an external circuit. The I/O electrode 7 is formed on a dielectric part having a dielectric constant lower than a dielectric part having the highest dielectric constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric filter,
The present invention relates to a structure of a dielectric coaxial resonator used for a high frequency device such as a dielectric duplexer and a voltage controlled oscillator (VCO).

[0002]

2. Description of the Related Art As a conventional dielectric coaxial resonator, one having the following structure is used. That is, as shown in FIGS. 7 and 8, the dielectric coaxial resonator 51 of the conventional example has a cylindrical dielectric block 53 having a through hole 52.
On the other hand, a ground electrode 55 is formed on the outer peripheral surface excluding the end surface 54, and an inner peripheral electrode 56 is formed on the entire inner peripheral surface of the through hole 52. Then, the inner peripheral electrode 56 and an external circuit (not shown)
An input / output electrode 57 is formed on one end face 54 in order to electrically connect the input and output electrodes 57 and 58 to each other. The input / output electrode 57 is connected to the dielectric coaxial resonator 5 through the opening on the one end face 54 side of the through hole 52.
1 is formed to extend to the mounting surface. An electrode non-formed portion 58 is provided on the mounting surface near the input / output electrode 57 to avoid electrical connection between the ground electrode 55 and the input / output electrode 57. The dielectric coaxial resonator 51 has the above configuration. In FIGS. 7 and 8, for convenience of description, the mounting surface is illustrated as being the upper surface of the drawing.

[0003]

However, the conventional dielectric coaxial resonator 51 has the following problems.

[0004] First, according to the configuration of the conventional example, the resonator 5
In general, it can be said that the electric field concentrates near the one end face 54 and the electric field strength becomes strong. At this time, when the input / output electrode 57 is formed on the one end face 54, the electromagnetic field in the TEM mode is The loss was greatly disturbed by the presence of the electrode 57, and the loss at the input / output electrode 57 was increased.

Further, fine adjustment of the resonance frequency of the resonator 51 is performed by cutting the dielectric material of the one end face 54 to change the dielectric constant. However, in order to reduce the size of the resonator, a material having a high dielectric constant is used. When used, the dielectric constant changes greatly even with minute cutting, making it difficult to make fine adjustments.

As another conventional example in which a plurality of dielectric portions having different dielectric constants are mixed to form a dielectric coaxial resonator, Japanese Patent Laid-Open No. 7-86813 is known. However, Japanese Patent Application Laid-Open No. 7-86813 only discloses that a dielectric coaxial resonator is simply composed of a plurality of dielectric materials. In order to solve the problems of the prior art shown first, However, it has not been clarified what kind of dielectric material should be disposed at what position.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned technical problems, and to reduce the loss at the input / output electrode portion and easily perform fine adjustment of the resonance frequency. It is another object of the present invention to provide a dielectric coaxial resonator.

[0008]

In order to achieve the above object, a dielectric coaxial resonator according to claim 1 of the present invention comprises a plurality of dielectric portions having different dielectric constants, which are formed in a mixed arrangement. Body block, a through hole formed in the dielectric block, a ground electrode formed on a predetermined outer peripheral surface of the dielectric block, and an inner peripheral electrode formed on the inner periphery of the through hole,
In a dielectric coaxial resonator having an inner peripheral electrode and an input / output electrode for electrically connecting an external circuit, the input / output electrode has a dielectric having the highest dielectric constant in each dielectric portion constituting the dielectric block. It is formed on a dielectric part having a lower dielectric constant than the body part.

According to a second aspect of the present invention, there is provided a dielectric coaxial resonator having a substantially rectangular parallelepiped shape having two end faces and four side faces, and formed by mixing and arranging a plurality of dielectric portions having different dielectric constants. A block, a through hole formed between two end surfaces of the dielectric block, a ground electrode formed on a predetermined outer peripheral surface excluding one end surface of the dielectric block, and a dielectric formed on the inner periphery of the through hole. An inner peripheral electrode electrically connected to the ground electrode on the other end surface of the block, and an input / output electrode extending from the inner peripheral electrode on one end surface of the dielectric block, and the four side surfaces of the dielectric block are provided. In a dielectric coaxial resonator that is mounted and used on a substrate or the like with one side surface as a mounting surface, the input / output electrodes are compared with the dielectric portion having the highest dielectric constant in each dielectric portion constituting the dielectric block. It is formed on the dielectric portion having a low dielectric constant.

According to a third aspect of the present invention, there is provided a dielectric coaxial resonator having a substantially rectangular parallelepiped shape having two end faces and four side faces, and formed by mixing and arranging a plurality of dielectric portions having different dielectric constants. A block, a through hole formed between two end surfaces of the dielectric block, a ground electrode formed on a predetermined outer peripheral surface excluding one end surface and the other end surface of the dielectric block, and a through hole formed on the inner periphery of the through hole. And an input / output electrode extending from the inner peripheral electrode at one end surface of the dielectric block, and one of the four side surfaces of the dielectric block is used as a mounting surface for a substrate or the like. In the dielectric coaxial resonator mounted and used in the above, the input / output electrode has a dielectric portion having a lower dielectric constant than the dielectric portion having the highest dielectric constant in each dielectric portion constituting the dielectric block. Shape on It is.

As described above, by disposing the low-dielectric-constant dielectric portion on one end face side where the input / output electrodes are formed, the intensity of the electric field concentrated on one end face can be reduced. By thus weakening the electric field intensity, it is possible to reduce the adverse effect on the TEM mode electromagnetic field due to the presence of the input / output electrodes.

Further, in the dielectric coaxial resonator according to claim 4 of the present invention, the ground electrode according to claim 2 or 3 is provided with input / output electrodes on four side surfaces of the dielectric block. At a predetermined distance from the edge on the one end surface side.

Thus, the intensity of the electric field concentrated near the one end face where the input / output electrode is formed can be further reduced.

According to a fifth aspect of the present invention, there is provided a dielectric coaxial resonator according to the second aspect of the present invention, wherein a through hole is provided at one end face of the dielectric block where the input / output electrodes are formed. A groove connecting the surface is provided, and an input / output electrode is formed on the groove.

Thus, when adjusting the resonance frequency,
There is no danger of cutting the input / output electrode part by mistake.

In addition, in the dielectric coaxial resonator according to a sixth aspect of the present invention, a part of the input / output electrodes according to the second to fifth aspects is extended to the mounting surface of the dielectric block. I have.

Thus, the degree of bonding between the input / output electrodes and the external circuit can be increased when mounting the dielectric coaxial resonator.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First Embodiment, FIGS. 1 to 3 First, as shown in FIGS. 1 and 2, a dielectric coaxial resonator 1 is one of a cylindrical dielectric block 3 having a through hole 2. The ground electrode 5 is provided on the outer peripheral surface excluding the end surface 4, and the inner peripheral electrode 6 is provided on the inner peripheral surface of the through hole 2.
Are respectively formed and configured. In order to electrically connect the inner peripheral electrode 6 to an external circuit (corresponding to reference numeral 10 in FIG. 3), an input / output electrode 7 is formed on one end surface 4. The input / output electrode 7 extends from the opening on the one end face 4 side of the through hole 2 to the mounting surface of the dielectric coaxial resonator 1. An electrode non-forming portion 8 is provided on the mounting surface near the input / output electrode 7 to avoid electrical connection between the ground electrode 5 and the input / output electrode 7. The ground electrode 5 and the inner peripheral electrode 6, and the input / output electrode 7 and the inner peripheral electrode 6 are electrically connected to each other through the opening of the through hole 2. The dielectric coaxial resonator 1 is configured as described above. (Fig. 1
In FIG. 2, for convenience of explanation, the mounting surface is shown so as to be the upper surface of the drawing.) The dielectric block 3 is composed of two types of dielectric portions having different dielectric constants. More specifically, as shown in FIGS. 1 and 2, a dielectric part 3 a having a low dielectric constant is provided on one end face 4 side of the through hole 2 in the longitudinal direction, and a dielectric part having a high dielectric constant is provided on the other end face side. 3b is arranged and configured. The dielectric block 3 is formed by integrally molding different dielectric materials by press molding, and then integrally firing.

As a material for the dielectric portions 3a and 3b, a ceramic mainly containing an oxide of a barium oxide-titanium oxide-lanthanide element or the like is used. A high conductivity material such as silver or copper is used for the ground electrode 5, the inner peripheral electrode 6, and the input / output electrode 7, respectively. These electrodes are formed by forming electrodes on the entire surface of the dielectric block 3 including the through holes 2 using a technique such as electroless plating, and then removing unnecessary portions by performing an etching process or the like.

The dielectric coaxial resonator 1 configured as described above is mounted on a circuit board, for example, as shown in FIG. That is, the dielectric coaxial resonator 1 is mounted on the circuit board 9 on which the external circuit 10 and the ground electrode 11 are formed, and the input / output electrodes 7 of the dielectric coaxial resonator 1 are connected to the external circuit 1.
The ground electrode 5 is electrically connected to the ground electrode 5 by a technique such as soldering (reference numeral 12 in FIG. 3 denotes a solder for connection).

[Second Embodiment, FIG. 4] In a dielectric coaxial resonator 11 according to a second embodiment of the present invention, as shown in FIG. It is formed at a distance from the edge on the one end face 4 side where the output electrode is formed. By forming the ground electrode 5 in this manner, the intensity of the electric field concentrated on the one end face 4 can be suppressed.

The other parts are the same as those of the dielectric coaxial resonator of the first embodiment, and the description thereof is omitted.

[Third Embodiment, FIG. 5] As shown in FIG. 5, a dielectric coaxial resonator 21 according to a third embodiment of the present invention has a through hole 2 in one end face 4 of the dielectric coaxial resonator 21. A groove 22 extending from the opening to the mounting surface is provided, and the input / output electrode 7 is provided on the groove 22. Thus, the groove 22
By forming the input / output electrode 7 on the concave groove 22, there is no fear that the input / output electrode 7 is deleted even when the end face is cut when the resonance frequency is adjusted.

The other parts are the same as those of the dielectric coaxial resonator of the first embodiment, so that the description thereof is omitted.

[Fourth Embodiment, FIG. 6] As shown in FIG. 6, a dielectric coaxial resonator 31 according to a fourth embodiment of the present invention comprises an input / output electrode of the dielectric coaxial resonator 21 of the third embodiment. 7 extends to the mounting surface. Thereby, the dielectric coaxial resonator 3
In mounting 1, the degree of bonding between the input / output electrodes and the external circuit is increased, and more reliable electrical connection can be performed.

The other parts are the same as those of the dielectric coaxial resonator of the first embodiment, so that the description thereof is omitted.

[Other Embodiments] The dielectric coaxial resonator according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention.
For example, the dielectric material forming the dielectric block is not limited to two types, and the dielectric block may be formed using three or more types of dielectric materials. In each of the above embodiments, the boundary between the dielectric portions forming the dielectric block is parallel to the end face of the dielectric block, but the boundary may be oblique. further,
By using a plurality of dielectric coaxial resonators in the above embodiment and providing a known coupling input / output means, any filter such as a band-pass filter, a band elimination filter, a high-pass filter, a low-pass filter, and other dielectric duplexers can be used. , VCO and the like.

[0029]

As is apparent from the above description, the following excellent effects can be obtained according to the dielectric coaxial resonator of the present invention.

First, the input / output electrodes are formed on the dielectric portion having a lower dielectric constant than the dielectric portion having the highest dielectric constant in each dielectric portion constituting the dielectric block. The loss in the input / output electrodes can be suppressed to a lower value. That is, since the electric field strength is weakened in the dielectric portion having a low dielectric constant, forming the input / output electrode on the dielectric portion having the low dielectric constant suppresses the disturbance of the TEM mode due to the presence of the input / output electrode to a lower level. You can do it.

Further, since the portion of the low dielectric constant material is cut when adjusting the resonance frequency, the change in the resonance frequency when the same amount of dielectric material is cut is different from that in the case of the high dielectric constant material alone. As a result, the resonance frequency can be finely adjusted easily.

Next, since the ground electrodes are formed on the four side surfaces of the dielectric block at a distance from the edge on the one end surface side where the input / output electrodes are formed, the intensity of the electric field concentrated near one end surface is obtained. Can be further reduced, and the loss at the input / output electrodes can be further suppressed.

Further, by arranging the input / output electrode on the concave groove formed on the one end face, there is no danger of erroneously cutting the input / output electrode portion when adjusting the resonance frequency.

In addition, by extending a part of the input / output electrode to the mounting surface, the degree of joining between the input / output electrode and the external circuit can be increased when the dielectric coaxial resonator is mounted, and the electrical continuity can be improved. Can be performed more reliably.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a dielectric coaxial resonator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a sectional view showing a mounted state of the dielectric coaxial resonator of the first embodiment.

FIG. 4 is a perspective view showing a dielectric coaxial resonator according to a second embodiment.

FIG. 5 is a perspective view showing a dielectric coaxial resonator according to a third embodiment.

FIG. 6 is a perspective view showing a dielectric coaxial resonator according to a fourth embodiment.

FIG. 7 is a perspective view showing a conventional dielectric coaxial resonator.

FIG. 8 is a sectional view taken along line XX of FIG. 7;

[Explanation of symbols]

1, 11, 21, 31, 51: dielectric coaxial resonator 2, 52: through hole 3, 53: dielectric block 3a, 3b: dielectric material 4, 54: one side End face 5, 55 ... Ground electrode 6, 56 ... Inner circumference electrode 7, 57 ... Input / output electrode 8, 58 ... Electrode non-formed part 9 ... Circuit board 10 ... External circuit 11 ... Ground electrode 12 ... Solder 22 ... Groove

Claims (6)

[Claims] 1. A dielectric block formed by mixing and arranging a plurality of dielectric portions having different dielectric constants, a through hole formed in the dielectric block, and a ground formed on a predetermined outer peripheral surface of the dielectric block. A dielectric coaxial resonator having an electrode, an inner electrode formed on the inner periphery of the through hole, and an input / output electrode for electrically connecting the inner electrode to an external circuit; A dielectric coaxial resonator formed on a dielectric part having a lower dielectric constant than a dielectric part having the highest dielectric constant in each dielectric part constituting a block. 2. A substantially rectangular parallelepiped dielectric block having two end faces and four side faces and formed by mixing and arranging a plurality of dielectric portions having different dielectric constants.
A through-hole formed between the two end surfaces, and a ground electrode formed on a predetermined outer peripheral surface excluding one end surface of the dielectric block,
An inner peripheral electrode formed on the inner periphery of the through hole and electrically connected to the ground electrode on the other end surface of the dielectric block, comprising an input / output electrode extending from the inner peripheral electrode on one end surface of the dielectric block, In a dielectric coaxial resonator used by being mounted on a substrate or the like using one of the four side surfaces of the dielectric block as a mounting surface, the input / output electrodes are most often used in each of the dielectric portions constituting the dielectric block. A dielectric coaxial resonator formed on a dielectric part having a lower dielectric constant than a dielectric part having a higher dielectric constant. 3. A substantially rectangular parallelepiped dielectric block having two end faces and four side faces and formed by mixing and arranging a plurality of dielectric portions having different dielectric constants.
A through-hole formed between the two end surfaces, a ground electrode formed on a predetermined outer peripheral surface excluding one end surface and the other end surface of the dielectric block, and an inner peripheral electrode formed on the inner periphery of the through hole,
An input / output electrode extending from an inner peripheral electrode at one end surface of the dielectric block, and a dielectric used by being mounted on a substrate or the like with one of the four side surfaces of the dielectric block as a mounting surface. In the coaxial resonator, the input / output electrodes are formed on a dielectric part having a lower dielectric constant than the dielectric part having the highest dielectric constant in each dielectric part constituting the dielectric block. A dielectric coaxial resonator characterized by the above-mentioned. 4. The ground electrode is formed at a predetermined distance from an edge on one end face side on which input / output electrodes are formed on four side surfaces of the dielectric block. The dielectric coaxial resonator according to claim 2 or 3. 5. A concave groove which connects a through hole and a mounting surface is provided on one end surface of the dielectric block where the input / output electrode is formed, and the input / output electrode is formed on the concave groove. 5. The dielectric coaxial resonator according to claim 2, wherein 6. The dielectric coaxial resonator according to claim 2, wherein a part of the input / output electrode extends to a mounting surface of the dielectric block.