JP2581913Y2 - TM mode dielectric resonator and TM mode dielectric filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TM mode dielectric resonator and a dielectric filter using the same.

[0002]

2. Description of the Related Art FIG. 12 is a cross-sectional view showing a structure of a conventional dielectric filter having a typical TM mode dielectric resonator. In FIG. 12, reference numerals 41, 42, 43, and 44 denote ceramic plates, respectively, on each of which an electrode film is formed at least on an inner surface thereof, and a ceramic cavity is formed by assembling these ceramic plates. In the same figure, reference numeral 40 denotes a columnar dielectric resonance element which is held between two ceramics plates 43-44 to be joined and integrated. Reference numeral 45 denotes a metal plate acting as a case bottom surface;
Is a metal cover that covers the top. The metal plate 45 and the metal cover 48 constitute a TM mode dielectric resonator case. In order to incorporate the dielectric resonator in this case, the ceramic plate 44 constituting a part of the ceramic cavity is made wider than the ceramic plate 43 to form a flange portion, and the strip-shaped metal plates 46 and 4 are formed.
7 is screwed and fixed to the metal plate 45 with screws,
After that, the metal cover 48 is screwed and fixed to the metal plate 45 with screws.

[0003]

However, in the conventional TM mode dielectric filter shown in FIG. 12, the components constituting the dielectric resonator are all made of ceramics, so that the material cost is high and the manufacturing process is extremely difficult. Therefore, there is a problem that the production cost is high because of the large number of the components. Of course, it has been conventionally devised to form a TM mode dielectric resonator and a filter using a metal cavity. However, a problem particularly in the TM mode dielectric resonator and a filter is that the metal material forming the cavity is a problem. Since the thermal expansion coefficient of the dielectric resonance element is greatly different from that of the dielectric resonance element, when used for high power, the heat generated by the element cannot keep the bonding state between the metal cavity and the dielectric resonance element stable. That is, in the TM mode dielectric resonator, a displacement current flows through the dielectric resonance element and an actual current flows through the cavity. Therefore, the change in the bonding state directly affects the characteristics, and reliability is a problem.

In the conventional dielectric resonator and the filter using the same, regardless of the material of the cavity,
As shown in FIG. 12, since the dielectric resonator is housed in the metal case to form the filter, a dead space 49 occurs in the part where the dielectric resonator is mounted in the case, and the entire filter becomes large. I was

An object of the present invention is to provide a low-cost TM mode dielectric resonator and a TM mode dielectric filter.

It is another object of the present invention to provide a TM mode dielectric resonator and a TM mode dielectric filter which are greatly reduced in size as a whole.

[0007]

According to the first aspect of the present invention, there is provided a TM mode dielectric resonator which can be bent and has elasticity.
A metal cavity is formed by bending a metal plate having at least two metal walls, and at least two inner wall surfaces of the metal cavity facing each other are depressed in a direction in which a facing interval is widened.
A concave portion is formed, and an end face of the dielectric resonance element is fitted into the concave portion of the metal cavity to elastically hold the dielectric resonance element in the metal cavity.

According to the TM mode dielectric filter of the present invention, a metal cavity is formed by bending a metal plate which can be bent and has elasticity, and at least two inner wall surfaces of the metal cavity facing each other. recessed to form a recess in the direction in which the plurality of opposing distance is widened to it the end faces of the recess in the dielectric resonance element of said metal cavity
Each of the plurality of dielectric resonators is elastically held in the metal cavity by fitting each other, and the dielectric resonators are coupled to each other, and a signal input / output coupling element is attached to a wall surface of the metal cavity.

According to a third aspect of the present invention, there is provided a TM mode dielectric resonator comprising: a hole formed in the metal cavity of the first aspect; and a metal plate covering the hole from an outer surface of the metal cavity. Do it.

According to a fourth aspect of the present invention, there is provided a TM mode dielectric filter, wherein the concave portion according to the second aspect includes a hole formed in the metal cavity and a metal plate covering the hole from an outer surface of the metal cavity. It becomes.

[0011]

In the TM mode dielectric resonator according to the first aspect of the present invention, the metal cavity is formed by bending a metal plate, and at least two concave portions are formed on at least two inner wall surfaces of the metal cavity facing each other. The end face of the dielectric resonance element is fitted into the recess of the metal cavity, and the dielectric resonance element is held in the metal cavity. By forming the cavity as a metal cavity formed by bending a metal plate as described above, it is possible to achieve a significant cost reduction as compared with the case where a ceramic cavity is formed. Moreover, unlike a completely rigid metal cavity, it has elasticity, so even if the cavity and the dielectric resonance element have different coefficients of thermal expansion, the mechanical distortion due to heat is completely absorbed by the elasticity of the metal cavity, and The junction between the and the dielectric resonance element is kept stable.

In the TM mode dielectric filter according to the second aspect, the cavity is a metal cavity formed by bending a metal plate, and a plurality of concave portions are formed on at least two inner wall surfaces of the metal cavity facing each other. The end face of the dielectric resonance element is fitted into the recess,
A plurality of dielectric resonance elements are arranged and held in the metal cavity, and the dielectric resonance elements are coupled. The coupling element for signal input / output is mounted on the wall surface of the metal cavity. With such a configuration, the metal cavity also functions as a case of the dielectric filter, and a special metal case is not required, so that the entire filter can be significantly reduced in size.

In the TM mode dielectric resonator according to the third aspect and the TM mode dielectric filter according to the fourth aspect, a hole is formed in the metal cavity, and the hole is covered with a metal plate from the outer surface of the metal cavity. ing. Thereby, when the dielectric resonator element is fitted into the concave portion of the metal cavity, first, the end face of the dielectric resonator element is fitted into the hole formed in the metal cavity, and then the hole is covered with a metal plate.
The end face of the dielectric resonance element can be held. For example, a concave portion is integrally formed in advance on one surface of the inner wall surface of the metal cavity by press working or the like, and the other inner wall surface has a hole and a metal plate as described in claim 3 or 4. When the concave portion is formed, the assembly of the dielectric resonance element in the metal cavity becomes easy.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a dielectric filter according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a metal plate before bending, which constitutes a part of a metal cavity. In FIG. 1, the metal plate 1 is composed of portions 20, 21, 22,..., 30, and the main portion of the metal cavity is constituted by making all the portions shown by broken lines valley-folded. In the figure, reference numeral 20 designates the bottom surface of the metal cavity in the arrangement shown in FIG.
1 and 22 constitute the sides of the metal cavity. 2
3, 24, 25, 26, 27 and 28 are mounting pieces for mounting a metal plate to which a connector is mounted as described later. 29 and 30 are mounting pieces for mounting the top surface of the metal cavity. Each mounting piece has a screw hole for screwing. Two concave portions 20a and 20b are formed in the bottom surface 20. In addition, mounting holes for mounting a coupling plate described later are formed in the side surfaces 21 and 22.

FIGS. 2 and 3 show the structure of the connector mounting plate. 2A is a left side view, and FIG.
Is a front view. As shown in FIG.
Is provided with a connector 3 on its outer surface and a coupling loop 12 for signal input / output on the side facing the inside of the cavity. 3A is a front view, and FIG. 3B is a right side view. As shown in the figure, the connector mounting plate 4 has a connector 5 mounted on the outer surface thereof and a signal input / output coupling loop 13 provided on the side facing the inside of the cavity.

FIG. 4 is a view showing the structure of a metal plate constituting the top surface of the metal cavity. 4A is a top view, FIG. 4B is a cross-sectional view taken along the line BB in FIG.
(C) is a sectional view taken along the line AA in (A). Two concave portions 6a and 6b are formed in the metal plate 6 constituting the top surface of the metal cavity as viewed from the inner surface of the cavity. At the short side of the metal plate 6, mounting pieces 31 and 32 for mounting the connector mounting plate shown in FIGS. 2 and 3 are formed.

FIG. 5 is a view showing the structure of the coupling plate provided in the metal cavity. The coupling plate 7 is provided with a window 8 for adjusting the coupling state and the coupling amount between the resonators on both sides of the coupling plate 7. Further, mounting pieces 33 and 34 for mounting on the two side surfaces of the metal cavity are provided on two opposite sides of the coupling plate 7, and the mounting holes provided on the side surfaces 21 and 22 shown in FIG. Secure with screws.

FIG. 6 is a top view before the metal plate serving as the top surface of the metal cavity is attached.

As described above, the metal plate shown in FIG. 1 is bent to form the main part of the metal cavity.
The coupling plate 7 is mounted inside the device, and the two prismatic dielectric resonator elements 10 and 11 are erected in concave portions (20a and 20b shown in FIG. 1) provided on the bottom surface. Thereafter, the metal plate 6 serving as the top surface shown in FIG.
The connector mounting plates 2 and 4 shown in FIG.

FIG. 7 is a cross-sectional view passing through two dielectric resonance elements of the TM mode dielectric filter configured as described above. FIG. 8 is a cross-sectional view passing through the dielectric resonator element 11 as viewed from the right side. In this way, a two-stage TM mode dielectric filter in which the two dielectric resonance elements 10 and 11 are held in the metal cavity is formed.

FIG. 9 is a partial cross-sectional view showing the state of the joint between the inner wall surface of the metal cavity and the dielectric resonance element. FIG.
In the above, an electrode film is formed in advance on the end face of the dielectric resonance element 10 by applying and baking an Ag paste, and the metal mesh 14 is sandwiched between the joining portions of the dielectric resonance element 10 to the concave portions 20a, and the Ag paste is formed. Are joined by baking.

Next, another structural example of the metal cavity is shown in FIG.
0 is shown. FIG. 10 is a cross-sectional view as viewed from the direction in which the dielectric resonance elements are arranged. Bottom 3 as in (A)
8, the top surface 37 and the two side surfaces 35 and 36 may be separately provided. Further, the main part of the metal cavity may be configured in such a manner that the metal cover 39 covers the bottom surface 40 as shown in FIG. Furthermore, as shown in (C), the bottom surface, the top surface, and the side surfaces may be formed of a single metal plate.

Next, FIG. 11 shows another structural example of the joint between the dielectric resonance element and the inner wall surface of the metal cavity. (A)
In the example shown in FIG. 5, a hole for fitting the end of the dielectric resonator element 10 is formed in the metal plate 6 forming the top surface of the metal cavity, and the concave portion is formed by covering the metal plate 6 ′ from outside the metal plate 6. Has formed. In the example shown in (B), the dielectric resonance element 1 is adjusted to the inner diameter A of the hole provided in the metal plate 6.
Positioning is performed by determining the shape of the 0 end face. One or a plurality of relatively small holes are formed in the metal plate 6 ′, and solder flows from the outside of the cavity into the holes provided in the metal plate 6 ′, and the solder flows through the metal mesh 14. To join the metal plate 6 ′ and the end face of the dielectric resonator element 10.

[0025]

[Effect of the invention] According to the TM mode dielectric resonator and the TM mode dielectric filter of this invention requires no ceramic cavity, Ru can be achieved significant cost. Also, a completely rigid metal cavity
Instead, it is formed by bending an elastic metal plate.
The elastic resonance of the dielectric resonator element in the metal cavity
The mechanical distortion due to heat is caused by the elasticity of the metal cavity.
Absorbed by the dielectric resonator element and the cavity
Reliability can be ensured. Also, the cavity
The end face of the dielectric resonator element is fitted and held in the recess.
Positioning of the dielectric resonator element with respect to the cavity
Becomes easier. Further, since a metal case for housing the cavity is not required, the whole can be significantly reduced in size.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state before bending a metal plate constituting a main part of a metal cavity according to a TM mode dielectric filter according to an embodiment of the present invention.

FIG. 2 is a view showing a structure of a connector mounting plate, and FIG.
Is a left side view, and (B) is a front view.

FIG. 3 is a view showing a structure of a connector mounting plate, and FIG.
Is a front view, and (B) is a right side view.

4A and 4B are diagrams showing a structure of a metal plate constituting a top surface of a metal cavity, wherein FIG. 4A is a top view, FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A, and FIG. A- in (A)
It is arrow sectional drawing of A.

5A and 5B are diagrams showing a structure of a coupling plate, wherein FIG. 5A is a front view, FIG. 5B is a right side view, and FIG. 5C is a top view.

FIG. 6 is a top view in the middle of assembling the TM mode dielectric filter.

FIG. 7 is a sectional view of a completed TM mode dielectric filter.

FIG. 8 is a sectional view of a completed TM mode dielectric filter.

FIG. 9 is a partial cross-sectional view showing a state of a joint between a dielectric resonator element and a metal cavity.

FIG. 10 is a view showing a structure of a metal cavity according to another embodiment.

FIG. 11 is a partial cross-sectional view showing a state of a joint between an end surface of the dielectric resonance element and an inner wall surface of the cavity.

FIG. 12 is a diagram showing a structure of a conventional TM mode dielectric filter.

[Explanation of symbols]

 1-Metal plate constituting the main part of metal cavity 2,4-Connector mounting plate 3,5-Connector 6-Metal plate constituting top surface of metal cavity 7-Coupling plate 8-Window portion 10,11-Dielectric Resonant element 12, 13-Signal input / output coupling loop 6a, 6b, 20a, 20b-Recess 14-Metal mesh

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kikuo Tsunoda 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto, Japan Murata Manufacturing Co., Ltd. Field surveyed (Int.Cl. ⁶ , DB name) H01P 7/10 H01P 1/20

Claims (4)

(57) [Scope of request for utility model registration] A metal cavity is formed by bending a metal plate that can be bent and has elasticity, and is recessed in at least two opposing inner wall surfaces of the metal cavity in a direction in which a facing interval is widened. Forming a recess,
The end surface of the dielectric resonator element is fitted into the concave portion of the metal cavity, and the dielectric resonator element is resiliently inserted into the metal cavity.
A TM mode dielectric resonator that maintains its properties . 2. A metal cavity is formed by bending a metal plate which can be bent and has elasticity, and a plurality of opposed spaces are formed on at least two inner wall surfaces of the metal cavity which are opposed to each other. a recess recessed, fitted to the end face of the dielectric resonance element in the recess of the metal cavity, respectively, the elastic are held a plurality of dielectric resonator element in the metal cavity, causes bonding the dielectric resonance element A TM mode dielectric filter, wherein a signal input / output coupling element is mounted on a wall surface of the metal cavity. 3. The TM mode dielectric resonator according to claim 1, wherein said concave portion comprises a hole formed in said metal cavity, and a metal plate covering said hole from an outer surface of said metal cavity. 4. The TM mode dielectric filter according to claim 2, wherein said concave portion comprises a hole formed in said metal cavity, and a metal plate covering said hole from an outer surface of said metal cavity.