WO2006001119A1

WO2006001119A1 - Dielectric resonator, dielectric filter, and method for fabricating dielectric filter

Info

Publication number: WO2006001119A1
Application number: PCT/JP2005/007974
Authority: WO
Inventors: Soichi Nakamura; Hideyuki Kato; Hirofumi Miyamoto; Hideki Tsukamoto
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2004-06-24
Filing date: 2005-04-27
Publication date: 2006-01-05
Also published as: JPWO2006001119A1; DE112005001123T5; JP4310469B2

Abstract

A dielectric filter (16) comprising a floating electrode part (7A) for regulating the resonance frequency and the capacitance and a floating electrode insulating part (15A) formed in a resonant conductor forming hole (2A). Consequently, machining area is reduced while attaining characteristic adjusting effects similar to those attained when the floating electrode part (7A) is removed entirely. Machining heat generated due to a small machining area is also reduced, and lowering of no-load Q and degradation of regulation accuracy due to physical property change of the dielectric filter (16) are suppressed. Reduction in size is also dealt with by employing laser machining.

Description

Technical field of dielectric resonator, dielectric filter, and method of manufacturing dielectric filter

The present invention relates to a dielectric resonator, a dielectric filter, and a dielectric filter manufacturing method applied to a high frequency circuit. Background art

FIG. 9 is a structural example of a conventional dielectric resonator using a dielectric block, and is an external perspective view thereof.

[0003] As shown in FIG. 9, a resonant conductor forming hole 2 in which a resonant conductor 3 is formed on the inner surface is provided inside a substantially rectangular parallelepiped dielectric block 1, and one of the resonant conductor forming holes 2 is provided. Outer conductors 4 are formed on the outer surfaces of the five surfaces excluding the end surfaces. The remaining surface of the dielectric block 1 is an open portion 5 where the outer conductor is not formed. The outer conductor 4 and the resonant conductor 3 constitute a dielectric resonator 17 having the open portion 5 as an open end face.

[0004] Further, as a dielectric filter provided with the dielectric resonator, there is a structure having a plurality of resonant conductor forming holes and input / output electrodes.

[0005] The method of adjusting the resonance frequency of these dielectric resonators, the frequency characteristics of the dielectric filter, the coupling coefficient of each resonator, and the coupling coefficient between the input / output electrode and the resonant conductor formation hole There is a method in which a part of a conductor is partially deleted (for example, see Patent Document 1).

[0006] In such a configuration, by providing a deletion portion in the resonant conductor, a conductor such as an input / output electrode or an adjacent resonance conductor provided in the outer conductor and a deletion portion facing the conductor are mutually connected. Adjust the capacitance to adjust the coupling coefficient. Further, in such a configuration, the resonance frequency is adjusted by changing the equivalent resonator length by forming a deletion site at a position facing the outer conductor.

[0007] When removing such a resonant conductor, a processing tool such as a reuter is used.

Patent Document 1: Japanese Patent Application Laid-Open No. 5-343903

Disclosure of the invention Problems to be solved by the invention

[0008] By the way, in the characteristic adjustment method by partial deletion of the resonant conductor, the characteristic can be adjusted by the position, size, and number of deleted parts. Heat is generated. This is accompanied by a decrease in adjustment accuracy due to changes in characteristics due to heat and a deterioration in unloaded Q value due to thermal reduction of dielectric ceramics.

[0009] In addition, along with the downsizing of the resonator, it is difficult to insert the part into the resonant conductor forming hole due to the size limit of the processing tool itself even when processing the deleted part using a mechanical processing tool.

Accordingly, an object of the present invention is to solve the above problems, improve the accuracy of characteristic adjustment, suppress characteristic deterioration, and cope with downsizing, a dielectric resonator, a dielectric filter, and a dielectric It is in providing the manufacturing method of a filter.

Means for solving the problem

(1) In the dielectric resonator according to the present invention, a resonant conductor forming hole in which a resonant conductor is formed on an inner surface is provided in the dielectric block, an outer conductor is formed on an outer surface of the dielectric block, and the resonant conductor An open portion of the resonant conductor is provided in the vicinity of at least one opening of the forming hole, and the floating electrode portion electrically insulated from the resonant conductor force is provided in or near the open portion, and the floating electrode portion And a floating electrode insulating part formed around the wire.

As described above, by providing the floating electrode and the floating electrode insulating portion, the shape of the resonant conductor of the resonator in which these are formed is changed, and the characteristics of the resonator are changed. At this time, by forming the deleted portion in a floating electrode shape, the deleted area is increased and the floating electrode insulating portion can be suppressed. Here, the same adjustment effect is obtained when only the floating electrode insulating part is deleted and when the floating electrode part itself is also deleted.

[0013] (2) Further, the dielectric resonator according to the present invention is characterized in that the open portion and the floating electrode insulating portion share a part of each.

[0014] This shape eliminates the need to delete the shared part, and therefore the area to be deleted can be suppressed to the remaining floating electrode insulating parts only.

[0015] (3) Further, in the dielectric resonator according to the invention, the open portion and the floating electrode insulating portion are separated. It is characterized by being formed away.

[0016] With this shape, there are no restrictions on the positions where the floating electrode portion and the floating electrode insulating portion are formed.

(4) Further, the dielectric resonator of the present invention is characterized in that two or more floating electrode portions are provided in or near the open portion provided in one resonance conductor forming hole. .

[0018] With this shape, even when the deleted area is increased by multiple adjustments, the deleted area can be minimized.

[0019] (5) Further, the dielectric filter of the present invention includes any one of the above-described dielectric resonators and input / output means coupled to the dielectric resonators.

[0020] With this configuration, the coupling coefficient between the resonator in which the floating electrode portion and the floating electrode insulating portion are formed as described above and the input / output electrodes, the coupling coefficient between the resonators, and the resonator length are used. When adjusting the frequency of the resonator, the area to be removed is limited to the floating electrode insulation by making the removed part a floating electrode. In this case as well, as with the dielectric resonator described above, The same adjustment effect can be obtained as when the electrode portion itself is deleted.

[0021] (6) In the dielectric filter manufacturing method of the present invention, the floating electrode insulating portion is formed in a region where the resonant conductor is formed, so that the resonant conductor force is separated and the floating electrode portion is formed. It is characterized in that the filter characteristics are determined by the resonant conductor removing process to be provided.

[0022] This resonance conductor removal step adjusts the resonance frequency of each resonator based on the coupling coefficient between the resonators, the strength of external coupling between the resonator and the input / output electrodes, and the resonator length. At this time, when the deletion part is made a floating electrode shape, the deletion area is limited to the floating electrode insulation part, and the floating electrode part and the floating electrode insulation part are both deleted while suppressing the deletion area. Achieve the same adjustment effect.

(7) The dielectric filter manufacturing method of the present invention is characterized in that the resonant conductor removing step is a conductor removing step by laser processing of the floating electrode insulating portion.

[0024] By the process by this processing method, processing is performed by irradiation from the outside of the resonant conductor forming hole regardless of the size of the resonant conductor forming hole.

The invention's effect [0025] (1) According to the present invention, since the deleted area can be suppressed only to the floating electrode insulating portion, it is possible to suppress degradation of no-load Q and change in characteristics due to heat generated during processing, and adjustment of the dielectric resonator. Accuracy can be improved.

[0026] (2) Further, according to the present invention, since the deleted area can be made only in the floating electrode insulating portion other than the shared portion, the heat generated during processing can be further suppressed, the deterioration of unloaded Q and the amount of characteristic change Can be suppressed, and the adjustment accuracy of the dielectric resonator can be improved.

[0027] (3) Further, according to the present invention, since there is no restriction on the determination of the formation location of the floating electrode portion and the floating electrode insulating portion, the degree of freedom in designing the dielectric resonator can be increased. .

[0028] (4) Further, according to the present invention, even when the deleted area is increased by multiple adjustments, the deleted area can be minimized, and no-load Q is deteriorated due to heat generated during processing. The characteristic change can be suppressed, and the adjustment accuracy of the dielectric resonator can be improved.

[0029] (5) Further, according to the present invention, the deleted area can be suppressed only to the floating electrode insulating portion.

In addition, it is possible to suppress deterioration of no-load Q and changes in characteristics due to heat generated during processing, and improve the adjustment accuracy of the dielectric filter.

[0030] (6) Further, according to the present invention, the deleted area can be suppressed only to the floating electrode insulating portion.

In addition, heat generated during processing and processing time can be suppressed, deterioration of the unloaded Q of the dielectric filter and characteristic change can be suppressed, and characteristic adjustment accuracy can be improved.

[0031] (7) Further, according to the present invention, by deleting the deleted portion by laser processing, the processing for adjusting the characteristics of the dielectric filter can be performed without inserting the processing tool into the resonant conductor forming hole. Can do.

In addition, when laser processing dielectrics, more heat is generated than when processing with a mechanical processing tool such as a leuter, and the amount of deterioration and characteristic change of unloaded Q is larger than when processing with a mechanical processing tool. There is a case. However, according to the present invention, since the deleted area is limited only to the area of the floating electrode insulating portion, generation of heat can also be suppressed. As a result, the amount of deterioration and characteristic change of no-load Q can be greatly suppressed.

In addition, the amount of change in characteristics before and after processing when recovering the degradation of no-load Q

By adopting the manufacturing method of the present invention, the size can be reduced. As a result, it is possible to improve the characteristic adjustment accuracy after the no-load Q recovery process. Brief Description of Drawings

FIG. 1 is an external perspective view of a dielectric filter according to a first embodiment.

[FIG. 2] In the dielectric filter according to the first embodiment, (A) is a BB cross-sectional view of FIG. 1, and (B) is an upper cross-section of FIG.

FIG. 3 is an enlarged view of a floating electrode part and a floating electrode insulating part according to the first embodiment, (A) is a front view, and (B) is a cross-sectional view.

FIG. 4 is an external view in a resonance conductor removing step according to the first embodiment.

FIG. 5 is a cross-sectional view taken along the line AA in the resonant conductor removal step according to the first embodiment.

FIG. 6 is a cross-sectional view taken along the line BB in the resonant conductor removing process according to the first embodiment.

FIG. 7 is an external perspective view of a dielectric filter according to a second embodiment.

FIG. 8 is a cross-sectional view of a dielectric filter according to a third embodiment.

FIG. 9 is an external perspective view of a conventional dielectric resonator.

Explanation of symbols

1-Dielectric block

2-resonant conductor formation hole

3-resonant conductor

4-outer conductor

5-open part

6-Input / output electrodes

7-Floating electrode

8-square

9-square

10 Laser reflection point

11 Laser reflector

12 Laser machining points

13 Laser generator

14 Coupling electrode

15 Floating electrode insulation 16—Dielectric filter

17—Dielectric resonator

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an external perspective view of the dielectric filter 16. FIG. 2 (A) is a cross-sectional view of the BB portion in FIG. FIG. 2B is a top view of the dielectric filter shown in FIG.

In FIG. 1, a substantially rectangular parallelepiped dielectric block 1 is provided with a plurality of resonant conductor forming holes 2A, 2B, and 2C provided with resonant conductors 3A, 3B, and 3C on their inner surfaces. The outer conductor 4 is provided on the five surfaces of the dielectric block 1 except for the upper end surface. Resonant conductor formation holes 2A, 2B, and 2C are provided so as to penetrate the upper end surface and the lower end surface of Fig. 1. The resonant conductors 3A, 3B, 3C and outer conductor 4 are connected to each other on the lower end surface of Fig. 1. Yes. In addition, input / output electrodes 6A and 6B are formed. Floating electrode portions 7A, 7B, and 7C and floating electrode insulating portions 15A, 15B, and 15C are formed at the upper ends of the resonant conductor forming holes 2A, 2B, and 2C, respectively. With this configuration, the dielectric filter 16 is a quarter-wave filter.

In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals. Cab represents the capacitance generated near the open area between the resonant conductors 3A and 3B. Cbc represents the capacitance generated near the open area between the resonant conductors 3B and 3C. Ce represents the capacitance generated between the resonant conductor 3C and the input / output electrode 6B. Ca represents the self-capacitance generated between the resonant conductor 3A and the outer conductor 4.

In FIG. 1, the floating electrode portion 7 A and the floating electrode insulating portion 15 A are formed in a portion facing the outer conductor 4. This structure shortens the equivalent resonator length of the resonator composed of the resonant conductor 3A, reduces the area where the resonant conductor 3A and the outer conductor 4 face each other, and reduces the self-capacitance (Ca in Fig. 2). . Due to changes in the resonator length and self-capacitance, the resonant frequency of the resonator by the resonant conductor 3A increases synergistically.

[0038] Further, the floating electrode portion 7B and the floating electrode insulating portion 15B are formed at portions facing the adjacent resonant conductor forming hole 2A. This structure shortens the equivalent resonator length of the resonator that also has the resonance conductor 3B force, and adjusts the resonance frequency higher. In addition, the structure reduces the opposing area on the open side of each of the resonant conductors 3 A and 3 B, and the capacitance between the resonators (Ca The coupling coefficient is adjusted by reducing b).

[0039] The frequency adjustment and the coupling coefficient adjustment are performed by changing the coupling coefficient between the resonators and the resonance frequency of the resonators when the floating electrode portion 7B and the floating electrode insulating portion 15B are long in the axial direction and short in the width direction. Can be done simultaneously. Further, when the floating electrode portion 7B and the floating electrode insulating portion 15B are short in the axial direction and long in the width direction, only the coupling coefficient between the resonators can be performed almost independently.

[0040] Further, the floating electrode portion 7C and the floating electrode insulating portion 15C are formed at a portion facing the input / output electrode 6B. With this structure, the equivalent resonator length of the resonator composed of the resonant conductor 3C is shortened and the resonance frequency is increased. This structure also reduces the capacitance (capacitance Ce in FIG. 2) between the resonator by the resonant conductor 3C and the input / output electrode 6B, and strengthens the external coupling between the resonator and the input / output electrode 6B. This is determined so that the floating electrode 7C and the floating electrode insulating portion 15C are not provided and become smaller than the case.

FIG. 3 (A) is an enlarged view of the floating electrode portion 7A and the floating electrode insulating portion 15A in the first embodiment. FIG. 3B is an enlarged cross-sectional view of the YY cross section in FIG.

In FIG. 3 (A), 9A, 9B, 9C, and 9D are angles in contact with the resonant conductor of the floating electrode insulating part, and 8A, 8B, 8C, and 8D are angles in contact with the floating electrode part of the floating electrode insulating part. It is.

In this embodiment, the floating electrode portion 7A and the floating electrode insulating portion 15A formed on the resonant conductor are partially shared by the sides 9A-9D. In addition, the width of each side of the floating electrode insulating portion 15A is 0.05 mm, the length is 0.45 mm for the sides 8A-8B, and 0.5 mm for the 9B-9C. Further, in FIG. 3B, the floating electrode insulating portion 15A is formed into a groove shape having a depth of 5 m, and the outer conductor 4 and the floating electrode portion 7A are insulated.

Here, the deleted area in the conductor deleting step is compared between the case where the floating electrode portion 7A and the floating electrode insulating portion 15A are present and the case where the floating electrode portion 7A is removed. In FIG. 2A, when there is a floating electrode portion 7A and a floating electrode insulating portion 15A, the conductor removal area is 0.07 square mm. On the other hand, when the floating electrode portion 7A is also removed, the conductor removal area is 0.25 mm 2. Compared with the case where the floating electrode portion 7A is removed, this embodiment suppresses the deleted area to 1 / 3.5 or less. By controlling the deleted area, the generation of processing heat is reduced, and deterioration of no-load Q and changes in characteristics in the dielectric resonator are suppressed. Next, a method for adjusting the characteristics of the dielectric filter shown in FIGS. 1 to 3 will be described with reference to FIGS. 4 to 6. In these figures, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

4 to 6 are diagrams in the characteristic adjustment process of the dielectric filter. FIG. 5 is a diagram showing the left side force of the dielectric filter in the state shown in FIG. 1, and the dielectric filter portion is shown as a cross-sectional view of the AA portion shown in FIG. Similarly, FIG. 6 is a view of the dielectric filter as viewed from the front side surface in the state shown in FIG. 1, and the dielectric filter portion is shown as a cross-sectional view of the BB portion shown in FIG. FIG. 4 is a diagram of the dielectric filter viewed from above in the state shown in FIG.

In FIG. 4, the laser emission port of the laser generator 13 is caused to perform a two-dimensional operation on a horizontal plane. The laser emitted laser also reflects the laser emitted perpendicularly to the horizontal plane with reflection points 10A to 11D of the reflecting mirrors 11A to 11D: LOD. By changing the coordinates of the laser trajectory from the horizontal plane to the vertical plane using the reflector, the laser can draw a two-dimensional trajectory on the vertical plane at the processing points 12A to 12D.

[0048] For example, in FIG. 5, when the laser is emitted so as to be reflected by the laser reflecting mirror 11A and the processing point 12A is processed, in FIG. 4, the laser is caused to draw an orbit like an arrow at the reflecting point 10A. . The laser reflected at the reflection point 10A is drawn with a trajectory similar to the arrow at the reflection point 1 OA at the processing point 12A, and the resonant conductor is removed. At that time, at laser processing point 12A, the laser can draw a trajectory that goes from corner 9A to corner 9B in Fig. 3 and then to corners 9C and 9D. Along the laser orbit, the floating electrode insulating portion 15A is removed to form the floating electrode portion 7A.

[0049] Similarly, when the laser beam is emitted so as to be reflected by the laser reflector 11B and the machining point 12B is machined, the trajectory similar to the arrow of the reflection point 10B is drawn at the machining point 12B and floated. The floating electrode insulating portion 15B is removed to form the floating electrode portion 7B.

[0050] Similarly, when the laser beam is emitted so as to be reflected by the laser reflecting mirror 11C and the processing point 12C is processed, the processing point 12C floats by drawing a trajectory similar to the arrow of the reflection point 10C. Remove electrode insulation 15C. Similarly, the laser is emitted so as to be reflected by the laser reflector 11D, and a trajectory similar to the arrow at the reflection point 1 OD is drawn at the processing point 12D. Remove floating electrode insulation 15D. The floating electrode portion 7 is formed by processing the floating electrode insulating portion 15C and processing the floating electrode insulating portion 15D.

[0051] As described above, the processing is performed by the laser, but since the deleted area of the electrode is only the area of the floating electrode insulating portion, the generation of heat is largely suppressed, and the electrode and the dielectric ceramic are reduced or made into a semiconductor. Can be prevented. As a result, the amount of deterioration and characteristic change of no-load Q can be greatly suppressed.

In this way, since the degradation of no-load Q can be suppressed, the amount of change in characteristics before and after the process when recovering the no-load Q can be suppressed. The characteristic adjustment accuracy can also be improved.

FIG. 7 is an external perspective view of the dielectric filter 16 in which both end faces of the resonant conductor forming holes 2A to 2C are open portions 5A and 5B. The dielectric filter 16 is a half-wave filter. Yes.

In this embodiment, coupling electrodes 14A to 14F are provided in the open portions 5A and 5B.

In the resonant conductor forming hole 2A, a part of the floating electrode portion 7A that has a shape extending over the resonant conductor forming hole 2A and the coupling electrode 14A, and a balanced shape between the resonant conductor forming hole 2A and the coupling electrode 14D. A part of a floating electrode 7E is provided. The resonant conductor forming hole 2B is provided with a floating electrode portion 7B having a shape extending over the resonant conductor forming hole 2A and the coupling electrode 14A. The resonant conductor forming hole 2C is provided with a floating electrode portion 7C having a shape in which an open portion and a floating electrode insulating portion are separately formed.

Further, the coupling electrode 14A is provided with a part of the floating electrode portion 7A having a shape extending over the resonance conductor forming hole 2A and the coupling electrode 14A. The part on the side of the coupling electrode 14A and the part on the side of the resonance conductor forming hole 2A constitute the floating electrode part 7A.

[0055] The coupling electrode 14B is provided with a part of the floating electrode portion 7B having a shape extending over the resonant conductor forming hole 2B and the coupling electrode 14B. The part on the coupling electrode 14B side and the part on the resonance conductor forming hole 2B side constitute a floating electrode part 7B. At the same time, the floating electrode 7D is provided on the coupling electrode 14B so as to share part of the end of the coupling electrode.

[0056] Further, the coupling electrode 14D spans the resonance conductor forming hole 2A and the coupling electrode 14D. A part of the floating electrode portion 7E having a shape is provided. The part on the coupling electrode 14D side and the part on the resonance conductor forming hole 2A side constitute a floating electrode part 7E.

[0057] In the conductor removal step by laser in the embodiment, the floating electrode portions 7A to 7D are formed in the same manner as the conductor removal step in the first embodiment. Further, in the conductor removal step of the floating electrode portion 7E, the dielectric filter 16 is turned upside down and the open portion 5B is disposed so as to face the laser generator 13 of FIG. 6, and the conductor removal step of the first embodiment is performed. It is formed in the same way as

Fig. 8 shows a resonator in which the outer conductor 4 is formed on both end faces of the resonant conductor forming holes 2A to 2C, and the resonant conductor non-formed portions 5A to 5C are annularly provided on the inner surface of the resonant conductor forming hole. is there . With this configuration, the dielectric filter 16 is a quarter-wave filter. In the resonant conductor forming hole 2A, the floating electrode portion 7A has a shape partially shared with the open portion 5A. Also in the resonant conductor forming hole 2B, the floating electrode insulating portion 15B has a shape partially shared with the open portion 5B, and two floating electrode portions 7B and 7C are formed at the same time. In the resonant conductor forming hole 2C, the floating electrode insulating portion 15C is formed separately from the open portion 5C, and the floating electrode portions 7D and 7E are formed at the same time.

[0059] Like the floating electrode portions 7B and 7C and the floating electrode portions 7D and 7E, by increasing the number of floating electrodes, additional adjustment can be performed even if the target characteristic is not reached by one adjustment. .

[0060] In the conductor removal step by laser in the present embodiment, the floating electrode portions 7A to 7E are removed in the same manner as the conductor removal step in the first embodiment.

An example of the structure of a dielectric duplexer comprising the dielectric filter of claim 5 is a dielectric duplexer comprising two sets of the filters shown in the first to third embodiments in one dielectric block. A structure having one excitation hole for coupling each filter and three input / output electrodes including a common input / output electrode can be mentioned. Even when a dielectric duplexer is configured in this way, by forming the floating electrode part and the floating electrode insulating part by the method shown in the first to third embodiments, the unloaded Q value is lowered and the adjustment accuracy is deteriorated. And suppress. As a result, the pass frequency band can be easily adjusted. In the first embodiment and the second embodiment described above, the resonant conductor forming hole is formed as a step hole having a square cross section and a circular cross section. It may be a hole with a single cross-sectional shape. Further, the cross-sectional shape may be a square shape, a circular shape, an elliptical shape, or an oval shape.

Claims

The scope of the claims

[1] A resonant conductor forming hole in which a resonant conductor is formed on the inner surface is provided in the dielectric block, an outer conductor is formed on the outer surface of the dielectric block, and the at least one opening of the resonant conductor forming hole is near the opening. In a dielectric resonator provided with an open portion of a resonant conductor,

A dielectric resonance comprising: a floating electrode part electrically insulated from the resonance conductor force; and a floating electrode insulation part formed around the floating electrode part at or near the open part. vessel.

2. The dielectric resonator according to claim 1, wherein the open portion and the floating electrode insulating portion share a part of each.

3. The dielectric resonator according to claim 1, wherein the open portion and the floating electrode insulating portion are separately formed.

[4] The method according to any one of claims 1 to 3, wherein two or more floating electrode portions are provided in or near the open portion provided in one resonance conductor forming hole. Dielectric resonator.

[5] A dielectric filter comprising the dielectric resonator according to any one of claims 1 to 4 and input / output means coupled to the dielectric resonator.

[6] The method for producing a dielectric filter according to claim 5,

The dielectric is characterized in that a filter characteristic is determined by a resonant conductor removing step of providing the floating electrode portion separately from the resonant conductor by forming the floating electrode insulating portion in a region where the resonant conductor is formed. A method for manufacturing a filter.

7. The dielectric filter manufacturing method according to claim 6, wherein the resonant conductor removing step is a conductor removing step by laser processing of the floating electrode insulating portion.