JPH07231205A - Dielectric coaxial resonator and dielectric filter - Google Patents

Abstract

PURPOSE:To obtain an inexpensive small dielectric coaxial resonator and dielectric filter with high quality less in the dispersion of the characteristic by reducing the number of components and manufacturing man-hours. CONSTITUTION:A resonator hole 2 whose inner circumferential face is formed with an inner conductor 3 is provided inside a dielectric block 1, and an outer conductor 4 is formed on the outer side of the dielectric block 1. Then a step 1c is provided on a bottom of the dielectric block 1 toward its open end face 1a, and part of the inner conductor 3 in the resonator hole 2 is in contact with the step 1c. The dielectric resonator and a coupling circuit such as a coupling board are directly connected by the inner conductor 3 in contact with the step 1c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a dielectric coaxial resonator in which a resonator hole is formed in a dielectric block and an outer conductor is formed on the outer surface of the dielectric block, and the dielectric coaxial resonator. The present invention relates to a constructed dielectric filter.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional dielectric coaxial resonator in which one resonator hole is formed in a dielectric block. In addition,
In the following figures, the dot-filled portions indicate portions where the base material such as the dielectric block and the substrate is visible (conductor non-formation portion).

In FIG. 4, one resonator hole 2 is formed in a dielectric block 1 so as to penetrate between a pair of opposed end surfaces 1a and 1b, and an inner conductor is formed on the inner peripheral surface of the resonator hole 2. 3 is formed. One opening surface 1a of the resonator hole 2 (hereinafter,
The outer conductor 4 is formed on other surfaces except the open end surface). The inner conductor 3 is electrically connected (short-circuited) with the outer conductor 4 at the other opening surface 1b (hereinafter, referred to as a short-circuit side end surface) of the resonator hole 2 facing the open-side end surface 1a, and the open-side end surface 1a.
Is separated (open) from the outer conductor 4.

Usually, the dielectric coaxial resonator is used as a filter, a trap or the like by connecting a capacitive element, an inductance element or the like.

When a filter is constructed using such a conventional dielectric coaxial resonator, for example, as shown in FIG. 5, a base substrate 30 on which an input / output electrode 31, an earth electrode 32, etc. are formed. On top of this, the three dielectric coaxial resonators and the coupling substrate 10 on which the coupling electrodes 11 for forming capacitors and the like are formed are mounted, and each dielectric coaxial resonator is
The connection terminal 20 made of metal is used to connect to the combined substrate 10.

Specifically, the connection terminal 20 is formed into a tongue shape by press-fitting the one end side formed in a substantially cylindrical shape into the resonator hole 2 of the dielectric coaxial resonator to conduct with the inner conductor 3. The other end side is soldered and connected to a coupling electrode 11 that forms a capacitance and the like formed on the coupling substrate 10, and the outer conductor 4 of the dielectric coaxial resonator is soldered to a ground electrode 32 of the base substrate 30. And then connected.

[0007]

However, when a filter is constructed using the above-mentioned conventional dielectric coaxial resonator,
A connection terminal is required to connect the dielectric coaxial resonator to a coupling circuit such as a coupling substrate on which capacitance or inductance is formed or mounted, and furthermore, the connection terminal is press-fitted into the dielectric coaxial resonator and assembled. Work is needed. That is, when the above-mentioned conventional dielectric coaxial resonator is used, a connecting component for inputting / outputting the dielectric coaxial resonator is necessarily required. Therefore, there is a problem that the cost of parts is increased, the number of manufacturing processes is increased, and the manufacturing cost is increased.

Further, in the above-mentioned conventional connection terminal connection, an inductance component is formed in the tongue-shaped portion of the connection terminal, and this inductance causes characteristic variations.

Therefore, an object of the present invention is to solve the above problems of the conventional dielectric coaxial resonator and the dielectric filter, reduce the number of parts, reduce the number of manufacturing steps, and reduce the cost. An object of the present invention is to provide a high-quality dielectric coaxial resonator and a dielectric filter with small variations.

[0010]

In order to achieve the above object, the invention according to claim 1 provides a resonator hole inside a dielectric block, and forms an inner conductor on the inner peripheral surface of the resonator hole. Then
In a dielectric coaxial resonator having an outer conductor formed on the outer surface of a dielectric block, a step portion is provided on the open end surface side of the dielectric block, and a part of the inner conductor is formed so as to contact the step portion. It is characterized by that.

According to a second aspect of the present invention, in the first aspect of the invention, a connection electrode is formed in the step portion of the dielectric block, the connection electrode being electrically connected to the inner conductor in the portion in contact with the step portion of the dielectric block. To do.

An invention according to claim 3 is a dielectric filter characterized by using at least one dielectric coaxial resonator according to claim 1 or 2.

[0013]

[Operation] Using the dielectric coaxial resonator having the above structure,
When constructing a filter, etc., the inner conductor of the portion in contact with the stepped portion of the dielectric block, or the connection electrode formed on the stepped portion of the dielectric block that conducts with this inner conductor, and the coupling formed on the coupling substrate It can be directly connected to the electrodes for use. Therefore, another component such as a connection terminal for connecting the dielectric coaxial resonator to the substrate or the like becomes unnecessary.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. In the figure, the same parts as those in the conventional example are designated by the same reference numerals.

FIG. 1 shows a dielectric coaxial resonator which is a first embodiment of the present invention. FIG. 1 is an external perspective view of a dielectric coaxial resonator.

As shown in FIG. 1, in the dielectric coaxial resonator of the present embodiment, one resonator hole 2 is formed so as to penetrate a dielectric block 1 having a substantially rectangular parallelepiped shape. The inner conductor 3 is formed on the peripheral surface. A step portion 1c is provided on the bottom surface (upper surface in the figure) of the dielectric block 1 and on the open side end surface 1a side which is one opening surface of the resonator hole 2 and is formed in the resonator hole 2. Part of the inner conductor 3 is formed so as to contact the step portion 1c.

An outer conductor 4 is formed on the outer surface of the dielectric block 1 excluding the open end surface 1a and the step portion 1c. The inner conductor 3 is separated (open) from the outer conductor 4 on the open side end face 1a side, and electrically connected (short circuit) to the outer conductor 4 on the short side end face 1b.
Has been done.

When a filter is constructed using the dielectric coaxial resonator of the above embodiment, as shown in FIG.
On the base substrate 30 on which the input / output electrodes 31 and the ground electrode 32 and the like are formed, for example, three dielectric coaxial resonators and the coupling substrate 10 on which the coupling electrodes 11 and the like are formed are mounted.

Specifically, the step portion 1 of the dielectric coaxial resonator
Part of the coupling substrate 10 is attached to c, and the inner conductor 3 at a portion in contact with the step portion 1c of each dielectric coaxial resonator and the coupling electrode 11 formed on the coupling substrate 10 are soldered to each other. The dielectric coaxial resonator and the coupling substrate 10 are connected and fixed. Then, the ground electrode 32 formed on the base substrate 30 and the outer conductor 4 on the bottom surface of each dielectric coaxial resonator are soldered,
A coupling electrode or the like (not shown) formed on the lower surface of the coupling substrate 10 and an input / output electrode 31 or the like formed on the base substrate 30 are soldered to form an integrated dielectric filter.

Although not shown, a coupling electrode, a ground electrode and the like are also formed on the lower surface of the coupling substrate 10, and these electrodes form a coupling capacitance and the like. Further, instead of the coupling LC element formed by these electrodes, a capacitive element such as a capacitor and an inductance element such as a coil may be mounted on the coupling substrate.

Further, an input / output electrode 31, an earth electrode 32, etc. are formed on the lower surface of the base substrate 30 so that they can be surface-mounted.

As described above, in the conventional dielectric coaxial resonator, the connection terminal is used for connection with the substrate. However, the dielectric coaxial resonator of this embodiment has a stepped portion on the bottom surface which is a mounting surface. A part of the inner conductor is formed in contact with the inner conductor, and the inner conductor in contact with the step portion and the coupling electrode formed on the joint substrate can be directly connected to each other.

Therefore, by using the dielectric coaxial resonator of the present embodiment, it is possible to use a separate connecting component such as a connecting terminal,
The dielectric coaxial resonator can be directly connected to the coupling substrate, and a filter or the like can be configured.

Next, FIG. 3 shows a dielectric coaxial resonator which is a second embodiment of the present invention. FIG. 3 is an external perspective view of the dielectric coaxial resonator.

As shown in FIG. 3, the dielectric coaxial resonator of this embodiment is similar to that shown in FIG. 1 of the first embodiment.
The bottom surface (top surface in the figure) of the dielectric block 1,
A step portion 1c is provided on the open side end surface 1a side which is one opening surface of the resonator hole 2, and a part of the inner conductor 3 formed in the resonator hole 2 is formed so as to contact the step portion 1c. Has been done.

In the dielectric coaxial resonator of this embodiment, the connection electrode 5 is formed around the inner conductor 3 in the portion in contact with the step portion 1c. The connection electrode 5 is formed to be electrically connected to the inner conductor 3 and separated from the outer conductor 4. Other configurations are the same as those shown in FIG. 1, and the description thereof will be omitted.

When a filter is constructed by using the dielectric coaxial resonator of the above embodiment, as described in FIG. 2 of the first embodiment, it is coupled to the step portion 1c of the dielectric coaxial resonator. Part of the substrate 10 is mounted, and the inner conductor 3 at a portion in contact with the step portion 1c of each dielectric coaxial resonator and the coupling electrode 11 formed on the coupling substrate 10 are soldered to each dielectric coaxial resonator. The resonator and the coupling substrate 10 are connected and fixed. And
The earth electrode 32 formed on the base substrate 30 and the outer conductor 4 on the bottom surface of each dielectric coaxial resonator are soldered, and a coupling electrode or the like formed on the lower surface of the joint substrate 10 (not shown)
The input / output electrodes 31 and the like formed on the base substrate 30 are soldered to form an integrated dielectric filter.

As described above, also in the dielectric coaxial resonator of this embodiment, without using separate connecting parts such as connecting terminals,
The dielectric coaxial resonator can be directly connected to the coupling substrate, and a filter or the like can be configured.

In this case, since the connection electrode which is electrically connected to the inner conductor is formed, the soldering area becomes large, and more stable soldering strength is obtained as compared with the dielectric coaxial resonator according to the first embodiment. As a result, the bond between the dielectric coaxial resonator and the coupling substrate becomes stronger.

The shape and size of the connection electrode are not limited to those shown in this embodiment, and the size and characteristics of the dielectric coaxial resonator, the size of the coupling electrode on the substrate, etc. are taken into consideration. Then, it may be set appropriately.

In each of the above embodiments, the inner conductor or connection electrode of the dielectric coaxial resonator is connected to each electrode formed on the coupling substrate, the dielectric coaxial resonator is connected to the base substrate, and the coupling substrate is connected. The connection between the base substrate and the base substrate has been described as the connection by soldering, but the connection is not limited to this, and the connection may be made with another conductive member such as a conductive adhesive or a silver paste.

In the above embodiment, the dielectric filter in which the dielectric coaxial resonator and the coupling substrate are arranged on the base substrate has been described. However, the base substrate is not necessarily required and the coupling filter is not necessary. An output electrode may be provided to form a dielectric filter that is integrated with the dielectric coaxial resonator and the coupling substrate.

Further, in the above embodiment, an example in which three dielectric coaxial resonators are mounted on the substrate has been described, but the present invention is not limited to this, and one, two or four or more may be mounted on the substrate. The dielectric coaxial resonator of the present invention can also be used in a trap or a filter in which the dielectric coaxial resonator is mounted.

[0034]

As described above, when a dielectric coaxial resonator according to the present invention is used to construct a filter or the like, the inner conductor of the portion in contact with the step portion of the dielectric coaxial resonator, or this inner conductor The dielectric coaxial resonator and the coupling circuit such as the coupling substrate can be directly connected to each other by the connection electrode that conducts with. That is, in the conventional dielectric coaxial resonator, a filter or the like can be configured without using the connecting parts such as the connecting terminals which are necessary for the input / output thereof.

Further, since the connection terminal is not used, an inductance component is not generated by the connection terminal,
It is possible to obtain a filter having stable characteristics with little variation.

Therefore, according to the present invention, it is possible to reduce the number of parts, and thus it is possible to greatly reduce the parts cost and the manufacturing cost, and to obtain a high-quality dielectric coaxial resonator and a dielectric material which are inexpensive and have a small characteristic variation. You can get a filter.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view showing a state in which the dielectric coaxial resonator shown in FIG. 1 of the present invention is mounted on a substrate to form a filter.

FIG. 3 is an external perspective view of a dielectric coaxial resonator according to a second embodiment of the present invention.

FIG. 4 is an external perspective view of a conventional dielectric coaxial resonator.

FIG. 5 is an exploded perspective view showing a state in which the conventional dielectric coaxial resonator shown in FIG. 4 is mounted on a substrate to form a filter.

[Explanation of symbols]

 1 Dielectric Block 1c Step Part 2 Resonator Hole 3 Inner Conductor 4 Outer Conductor 5 Connection Electrode 10 Coupling Substrate 30 Base Substrate

Claims (3)

[Claims] 1. A dielectric coaxial resonator in which a resonator hole is provided inside a 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 the dielectric coaxial resonator, a stepped portion is provided on the open end surface side of the dielectric block, and a part of the inner conductor is in contact with the stepped portion. 2. The dielectric coaxial resonator according to claim 1, wherein a connection electrode that is electrically connected to an inner conductor of a portion in contact with the step portion of the dielectric block is formed in the step portion of the dielectric block. 3. A dielectric filter, wherein at least one dielectric coaxial resonator according to claim 1 or 2 is used.