JPH0641361Y2 - TM mode dielectric resonator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a TM-mode dielectric resonator, and more particularly to an improved TM-mode dielectric resonator.

[Conventional technology]

As shown in FIG. 2, a dielectric resonator utilizing the TM ₁₁₀ mode has a dielectric pillar 2 housed in a conductive case 1 made of metal or a metal having a conductive layer formed on the outer surface thereof. It has a fixed structure. Electrodes 3 are formed on both end surfaces of the dielectric column 2, and the electrodes 3 are electrically connected to the conductive case 1. This type of dielectric resonator is widely used as a single resonator or a combination of a plurality of dielectric resonators.

Conventionally, a structure as shown in FIG. 3 has been used to couple the above-mentioned TM mode dielectric resonator with the outside. That is, the through hole 1a is formed in the conductive case 1, and the central conductor 5 of the coaxial connector 4 extends into the conductive case 1 through the through hole 1a. On the other hand, a hole 2a is formed at one end of the dielectric pillar 2, and the center conductor 5 of the coaxial connector is inserted in the hole 2a. Here, the external Q (Qe) is adjusted by changing the insertion length l of the central conductor 5.

[Problems to be solved by the invention]

However, in the above coupling structure, the hole 2a must be formed in the dielectric pillar 2, and it is difficult to accurately process such hole 2a. Further, since the central conductor 5 is inserted into the hole 2a, the central conductor 5 and the inner wall of the hole 2a tend to come into contact with each other during the adjustment. As a result, it was difficult to accurately adjust Qe to obtain a desired binding amount.

Therefore, an object of the present invention is to provide a TM mode dielectric resonator in which the amount of coupling with the outside can be easily adjusted and which has excellent workability in assembly.

[Means for solving problems]

The TM mode dielectric resonator of the present invention comprises a dielectric column and a conductive case that houses the dielectric column and that is electrically and mechanically connected to both ends of the dielectric column. On the side surface of the dielectric pillar, a connection electrode for external connection is formed so as not to be electrically connected to the conductive case. It is characterized in that a hole for electrically connecting with is formed.

[Action]

According to the present invention, a connection electrode fixedly provided on a side surface of a dielectric pillar is used to electrically connect to the outside and thereby connect to the outside. Therefore, it is possible to accurately and easily adjust the external Q (Qe) by trimming the connection electrode. Further, unlike the conventional example, there is no need for a step of processing a hole in the dielectric pillar.

[Explanation of Examples]

FIG. 1 is a sectional view showing an embodiment of the present invention. For example, a dielectric pillar 12 is provided in a conductive case 11 made of a material or metal plate obtained by coating the outer surface of a ceramic plate with a conductive layer.
Is stored. Although not shown in the drawing, the same dielectric pillars as the dielectric pillars 12 are arranged in the conductive case 11 with a predetermined distance therebetween, and each of them cooperates with the conductive case 11 to form the TM _110.
It constitutes a mode dielectric resonator, which constitutes a filter device such as a bandpass filter. The illustrated dielectric pillar 12 constitutes a resonator at the input or output stage of this filter device.

Electrodes 13a and 13b are formed on both end surfaces of the dielectric column 12, and are electrically connected to the conductive case 11 by the electrodes 13a and 13b. The electrodes 13a and 13b are formed, for example, by applying a silver paste to both end surfaces of the dielectric pillar 12 and baking the paste while contacting the inner surface of the conductive case 11, whereby the dielectric pillar 12 is physically formed. It is fixed to the conductive case 11.

Connection electrodes 17 are formed on the side surfaces of the dielectric columns 12.
The connection electrode 17 can be formed by applying a silver paste for forming the electrodes 13a and 13b to the side surface of the dielectric column 12 and baking the same at the same time as the electrodes 13a and 13b. However, it may be formed separately from the electrodes 13a and 13b or by another electrode forming method.

A hole 11a is formed in the conductive case 11 above the portion where the connection electrode 17 is formed. The hole 11a is formed to electrically connect the connection electrode 17 to the outside. That is, in this embodiment, the central conductor 15 of the coaxial connector 14 is extended into the conductive case 11 through the hole 11a, and the central conductor 15 is soldered to the connection electrode 17.
Soldered by 18 and electrically connected to the connecting electrode 17.

As described above, in the present embodiment, at the time of coupling with the outside, the central conductor 15 of the coaxial connector is directly soldered and connected to the connection electrode 17 fixedly formed on the side surface of the dielectric column 12. . Therefore, it is understood that the variation of the coupling amount due to the contact of the central conductor 5 with the inner surface of the hole 2a does not occur unlike the conventional example shown in FIG.

In addition, the amount of coupling can be adjusted easily and accurately by trimming the connection electrode 17. Moreover, it is not necessary to form the hole 2a in the dielectric column 12 as in the conventional example.

When the connection electrode 17 is trimmed, the strength of the coupling is adjusted to be weaker. On the other hand, in a wideband type bandpass filter with a normal bandwidth of about 400 MHz, stronger coupling with the outside is required, but adjustment is made to strengthen the coupling with the outside in this way. It is also possible.

That is, as shown in FIG. 4, the corner portion may be removed by cutting on one end side of the dielectric pillar 12. In this case, as schematically shown in FIG. 5, it is formed between the connection electrode 17 and the other electrode 13b of the capacitance C ₁ formed between the one electrode 13a and the connection electrode 17. The ratio to the capacity C ₂ can be reduced. Therefore, in the equivalent circuit of FIG. 6, the C ₁ / C ₂ ratio becomes smaller, so that the external circuit can be more strongly coupled. As described above, according to the present embodiment, it is possible to easily adjust the degree of coupling with the outside to either weaken or strengthen.

As the shape of the dielectric pillar 12, various shapes such as a columnar shape or a prismatic shape can be used. Further, although not particularly shown, when a plurality of dielectric resonators are combined to form a filter device, both the input stage and the output stage may be configured as shown in FIG. 1, or Only one of them may be constructed as shown in FIG. Further, in the embodiment of FIG. 1, the external connection is made by using the coaxial connector 14, but the external connection may be made electrically by other connecting means.

[Effect of device]

According to the present invention, in the TM mode dielectric resonator, the connection electrode for external coupling is formed on the side surface of the dielectric pillar so as not to be electrically connected to the conductive case. Since the case has a hole for electrically connecting the connection electrode to the outside, the connection electrode fixedly provided on the dielectric pillar can be used to couple with the outside. Therefore, the amount of external coupling can be set accurately. Moreover, since it is not necessary to form a hole in the dielectric column as in the conventional example, the workability in assembling can be dramatically improved.

In addition, when adjusting the strength of the bond with the outside, it can be done by trimming the connecting electrodes or cutting and removing a part of the dielectric pillar, so that the strength of the bond can be weakened. Can also be easily adjusted.

It should be pointed out that the dielectric resonator of the present invention is suitable for a bandpass filter having a normal bandwidth of 400 MHz, for example, because it can be easily adjusted to enhance the coupling with the outside. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a perspective view for explaining a TM mode dielectric resonator, FIG. 3 is a sectional view of a conventional dielectric resonator, and FIG. Is a cross-sectional view of the embodiment of FIG. 1 adjusted to enhance the coupling with the outside, FIG. 5 is a schematic view of the structure of FIG. 4, and FIG. 6 is an equivalent circuit of the structure shown in FIG. Show. In the figure, 11 is a conductive case, 12 is a dielectric pillar, and 13a and 13b.
Is an electrode, and 17 is a connecting electrode.

Claims (1)

[Scope of utility model registration request] 1. A side surface of the dielectric pillar, comprising: a dielectric pillar; and a conductive case that houses the dielectric pillar and is electrically and mechanically connected to both ends of the dielectric pillar. In, the connection electrode for taking a coupling with the outside is formed so as not to be electrically connected to the conductive case, and the conductive case electrically connects the connection electrode to the outside. Characterized in that a hole for forming is formed
TM mode dielectric resonator.