JP4310469B2 - Dielectric resonator, dielectric filter, and method of manufacturing dielectric filter - Google Patents

Description

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

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

  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, excluding one end face of the resonant conductor forming hole 2. Outer conductors 4 are formed on the outer surfaces of the five surfaces. The remaining one 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.

  In addition, some dielectric filters having the dielectric resonator have a structure having a plurality of resonant conductor forming holes and input / output electrodes.

  To adjust the resonance frequency of these dielectric resonators, the frequency characteristics of the dielectric filter, the coupling coefficient between the resonators, and the coupling coefficient between the input / output electrodes and the resonant conductor formation hole, There is a method of partially deleting (see, for example, Patent Document 1).

  In such a configuration, the mutual capacitance is adjusted between the input / output electrodes provided on the outer conductor and the adjacent resonant conductor, etc., and the deleted part facing the conductor by providing the deleted part on the resonant conductor. Then, the coupling coefficient is adjusted. Further, in such a configuration, the resonance frequency is adjusted by changing the equivalent resonator length by forming a deletion portion at a position facing the outer conductor.

When removing such a resonant conductor, a processing tool such as a router is used.
JP-A-5-343903

  By the way, in the characteristic adjusting method by partial deletion of the resonant conductor, the characteristic can be adjusted by the position, size, and number of deleted parts. However, in the method using a mechanical processing tool such as the luter, heat is generated at the time of deletion. For this reason, there is a decrease in adjustment accuracy due to a characteristic change due to heat, and a deterioration in unloaded Q value due to thermal reduction of the dielectric ceramics.

  Further, along with the downsizing of the resonator, it is difficult to insert the inside of the resonant conductor forming hole due to the size limit of the processing tool itself in processing of the deleted portion using the mechanical processing tool.

  Accordingly, an object of the present invention is to solve the above-described problems, improve the accuracy of characteristic adjustment, suppress characteristic deterioration, and cope with miniaturization. A dielectric resonator, a dielectric filter, and a dielectric filter manufacturing method Is to provide.

(1) In the dielectric resonator according to the present invention, 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 at least the resonant conductor forming hole is provided. An open portion having an open end adjacent to the end of the resonant conductor is provided near one opening, and the floating electrode is electrically insulated from the resonant conductor, and the floating A floating electrode insulating part formed around the electrode part is surrounded by a resonant conductor in the vicinity of the open part, or is surrounded by the resonant conductor and the open part .

  Thus, 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 changes, and the characteristics of the resonator change. At this time, by forming the deleted portion into a floating electrode shape, the deleted area is increased and only the floating electrode insulating portion is 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.

(2) Moreover, the dielectric resonator according to the present invention is characterized in that the open portion and the floating electrode insulating portion share a part thereof.

  With this shape, it is not necessary to delete the shared part, so that the area to be deleted can be suppressed only to the remaining floating electrode insulating parts.

(3) Further, the dielectric resonator according to the present invention is characterized in that the open portion and the floating electrode insulating portion are separately formed.

  Due to this shape, there are no restrictions on the formation positions of the floating electrode portion and the floating electrode insulating portion.

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

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

(5) The dielectric filter of the present invention is characterized by including any one of the above-described dielectric resonators and input / output means coupled to the dielectric resonator.

  With this configuration, the resonator having the floating electrode portion and the floating electrode insulating portion formed as described above and the coupling coefficient between the input / output electrodes, the coupling coefficient between the resonators, and the resonator length based on the resonator length When adjusting the frequency, the deleted area is made the floating electrode shape, so that the deleted area is suppressed only to the floating electrode insulating part, and in this case as well, the floating electrode part itself is the same as the dielectric resonator described above. The same adjustment effect can be obtained as when including and deleting.

(6) In the dielectric filter manufacturing method according to the present invention, the floating electrode insulating portion is formed in a region where the resonant conductor is formed, thereby providing the floating electrode portion separated from the resonant conductor. The filter characteristic is determined by the removing step.

  By this resonance conductor removing step, the resonance frequency of each resonator is adjusted 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, the same adjustment as when both the floating electrode part and the floating electrode insulating part were deleted while suppressing the deleted area by limiting the deleted area to the floating electrode insulating part by making the deleted part into a floating electrode shape. Realize the effect.

(7) Further, 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.

  By this process, a process is performed by irradiation from the outside of the resonant conductor forming hole regardless of the size of the resonant conductor forming hole.

(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 deterioration of the no-load Q and characteristic change due to heat generated during processing, and improve the adjustment accuracy of the dielectric resonator. Can be made.

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

(3) Moreover, according to this invention, since determination of the formation location of a floating electrode part and a floating electrode insulation part is not restricted, the freedom degree of design of a dielectric resonator can be made high.

(4) Further, according to the present invention, even when the deleted area is increased by multiple adjustments, the deleted area can be minimized, and deterioration of the unloaded Q due to heat generated during processing and characteristic changes Therefore, the adjustment accuracy of the dielectric resonator can be improved.

(5) Further, according to the present invention, since the deleted area can be suppressed only to the floating electrode insulating portion, it is possible to suppress deterioration of the no-load Q and characteristic change due to heat generated during processing, and to improve the adjustment accuracy of the dielectric filter. Can be improved.

(6) Further, according to the present invention, since the deleted area can be suppressed only to the floating electrode insulating portion, heat and processing time generated during processing can be suppressed, and deterioration of the unloaded Q of the dielectric filter and characteristic change can be prevented. This can be suppressed and the characteristic adjustment accuracy can be improved.

(7) Further, according to the present invention, by deleting the deleted portion by laser processing, it is possible to perform processing for adjusting the characteristics of the dielectric filter without inserting a processing tool into the resonance conductor forming hole.
In addition, when laser processing dielectrics, more heat is generated than when processing with a machine tool such as a leuter, and the amount of deterioration of the unloaded Q and the amount of change in characteristics increase compared to processing with a mechanical tool. There is. 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. Thereby, the deterioration amount and characteristic change amount of the no-load Q can be significantly suppressed.
Further, the amount of change in characteristics before and after the process when the process of recovering the deterioration of the no-load Q can be reduced by adopting the manufacturing method of the present invention. As a result, it is possible to improve the characteristic adjustment accuracy after the unloaded Q recovery process.

<First Embodiment>
FIG. 1 is an external perspective view of the dielectric filter 16. 2A is a cross-sectional view taken along the line BB in FIG. FIG. 2B is a top view of the dielectric filter shown in FIG.

  In FIG. 1, a substantially rectangular parallelepiped-shaped dielectric block 1 is provided with a plurality of resonance conductor forming holes 2A, 2B, 2C provided with resonance conductors 3A, 3B, 3C on the inner surfaces thereof. The outer conductor 4 is provided on the five surfaces except the upper end surface of the dielectric block 1. The resonant conductor forming holes 2A, 2B, and 2C are provided so as to penetrate the upper end surface side and the lower end surface side in FIG. 1, and the resonant conductors 3A, 3B, and 3C and the outer conductor 4 are electrically connected on the lower end surface side in FIG. . 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 wavelength filter.

  In FIG. 2, the same parts as those in FIG. Cab represents a capacitance generated in the vicinity of the open portion between the resonant conductors 3A and 3B. Cbc represents a capacitance generated near the open portion between the resonant conductors 3B-3C. Ce represents a capacitance generated between the resonant conductor 3C and the input / output electrode 6B. Ca represents a self-capacitance generated between the resonant conductor 3 </ b> A and the outer conductor 4.

  In FIG. 1, the floating electrode portion 7 </ b> A and the floating electrode insulating portion 15 </ b> A are formed in a portion facing the outer conductor 4. With this structure, the equivalent resonator length of the resonator composed of the resonant conductor 3A is shortened, the area where the resonant conductor 3A and the outer conductor 4 face each other is reduced, and the self-capacitance (Ca in FIG. 2) is reduced. . Due to the change in the resonator length and the self-capacitance, the resonance frequency of the resonator by the resonance conductor 3A is synergistically increased.

  Further, the floating electrode portion 7B and the floating electrode insulating portion 15B are formed in a portion facing the adjacent resonance conductor forming hole 2A. With this structure, the equivalent resonator length of the resonator composed of the resonance conductor 3B is shortened, and the resonance frequency is adjusted high. In addition, the coupling coefficient is adjusted by reducing the opposing area on the open side of each of the resonant conductors 3A and 3B and reducing the capacitance between the resonators (Cab in FIG. 2).

  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, the frequency adjustment and the coupling coefficient adjustment are performed simultaneously with the coupling coefficient between the resonators and the resonance frequency of the resonator. be able to. 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 substantially independently.

  Further, the floating electrode portion 7C and the floating electrode insulating portion 15C are formed in 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. In addition, the structure reduces the capacitance (capacitance Ce in FIG. 2) between the resonator by the resonant conductor 3C and the input / output electrode 6B, and the strength of external coupling between the resonator and the input / output electrode 6B. Is determined to be smaller than when there is no floating electrode 7C and floating electrode insulating portion 15C.

  FIG. 3A 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. 3A, 9A, 9B, 9C, and 9D are angles in contact with the resonant conductor of the floating electrode insulating portion, and 8A, 8B, 8C, and 8D are angles in contact with the floating electrode portion of the floating electrode insulating portion.

  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. Further, the width of each side of the floating electrode insulating portion 15A is 0.05 mm, and the length is 0.45 mm for the sides 8A-8B and 0.5 mm for 9B-9C. Further, in FIG. 3B, the floating electrode insulating portion 15A has a groove shape with a depth of 5 μm, and the outer conductor 4 and the floating electrode portion 7A are insulated.

  Here, the removal area in the conductor removal 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 square mm. 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 suppressing the deleted area, generation of processing heat is reduced, and deterioration of no-load Q and a change 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. 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. 5 is a view of the dielectric filter as viewed from the left side 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 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 view of the dielectric filter as 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 from the laser emission port vertically to the horizontal plane is reflected by the reflection points 10A to 10D of the reflecting mirrors 11A to 11D. The laser trajectory is coordinate-converted from the horizontal plane to the vertical plane by the reflecting mirror, thereby causing the laser to draw a two-dimensional trajectory on the vertical plane at the processing points 12A to 12D.

  For example, in FIG. 5, when the laser beam 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 reflection point 10A. The laser reflected at the reflection point 10A is made to draw a trajectory similar to the arrow of the reflection point 10A at the processing point 12A, and the resonant conductor is removed. At that time, at the laser processing point 12A, the laser is caused to draw a trajectory that proceeds from the corner 9A to the corner 9B in FIG. 3 and then proceeds to the corners 9C and 9D. Along the laser trajectory, the floating electrode insulating portion 15A is removed to form the floating electrode portion 7A.

  Similarly, when processing the processing point 12B by emitting the laser so as to be reflected by the laser reflecting mirror 11B, the floating electrode insulating portion 15B is drawn by drawing a trajectory similar to the arrow of the reflection point 10B at the processing point 12B. The floating electrode part 7B is formed by removing.

  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 floating electrode insulating portion 15C is formed by drawing a trajectory similar to the arrow of the reflection point 10C at the processing point 12C. Remove. Similarly, the laser is emitted so as to be reflected by the laser reflecting mirror 11D, and the floating electrode insulating portion 15D is removed by drawing a trajectory similar to the arrow of the reflecting point 10D at the processing point 12D. The floating electrode portion 7 is formed by processing the floating electrode insulating portion 15C and processing the floating electrode insulating portion 15D.

In this way, processing is performed with a laser, but since the area of the electrode to be deleted is only the area of the floating electrode insulating part, the generation of heat is greatly suppressed, and the electrode and dielectric ceramics are reduced or made semiconductor. Can be prevented. Thereby, the deterioration amount and characteristic change amount of the no-load Q can be significantly suppressed.
In this way, since the deterioration of the no-load Q can be suppressed, the amount of change in characteristics before and after the process when the process for recovering the no-load Q can be suppressed thereafter. Adjustment accuracy can also be improved.

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

  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 having a shape extending over the resonant conductor forming hole 2A and the coupling electrode 14A, and a floating extending in a shape extending over the resonant conductor forming hole 2A and the coupling electrode 14D are provided. A part of the 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.

  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 coupling electrode 14A side and the part on the resonance conductor forming hole 2A side constitute a floating electrode part 7A.

  The coupling electrode 14B is provided with a part of the floating electrode portion 7B having a shape extending over the resonance 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 coupling electrode 14B is provided with the floating electrode 7D so as to partially share the end of the coupling electrode.

  The coupling electrode 14D is provided with a part of the floating electrode portion 7E having a shape extending over the resonance conductor forming hole 2A and the coupling electrode 14D. 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.

  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. In the conductor removal step of the floating electrode portion 7E, the dielectric filter 16 is turned upside down and the opening 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 forms similarly.

<Third Embodiment>
FIG. 8 shows a resonator in which the outer conductor 4 is formed on both end surfaces of the resonant conductor forming holes 2A to 2C, and the resonant conductor non-formed portions 5A to 5C provided in an annular shape on the inner surface of the resonant conductor forming hole are open portions. . With this configuration, the dielectric filter 16 is a quarter wavelength 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 the 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 has a shape formed separately from the open portion 5C, and the floating electrode portions 7D and 7E are formed at the same time.

  By increasing the number of floating electrodes like the floating electrode portions 7B and 7C and the floating electrode portions 7D and 7E, additional adjustment can be performed without reaching the target characteristics by one adjustment.

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

<Fourth 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 filters shown in the first to third embodiments in one dielectric block. One having an excitation hole for coupling the respective filters and a structure having three input / output electrodes including a common input / output electrode can be mentioned. Even when the dielectric duplexer is configured as described above, the floating electrode portion and the floating electrode insulating portion are formed by the method described in the first to third embodiments, thereby reducing the no-load Q value and the adjustment accuracy. 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 quadrangular cross section and a circular cross section. However, as in the third embodiment, a single hole is formed. It may be a hole with a single cross-sectional shape. Further, the cross-sectional shape may be a quadrangular shape, a circular shape, an elliptical shape, or an oval shape, and the shape is not limited.

1 is an external perspective view of a dielectric filter according to a first embodiment. In the dielectric filter according to the first embodiment, (A) is a BB sectional view of FIG. 1, and (B) is an upper sectional view of FIG. It is an enlarged view of the floating electrode part and floating electrode insulation part which concern on 1st Embodiment, (A) is a front view, (B) is sectional drawing. It is an external view in the resonance conductor removal process which concerns on 1st Embodiment. It is AA sectional drawing in the resonance conductor removal process which concerns on 1st Embodiment. It is BB sectional drawing in the resonance conductor removal process which concerns on 1st Embodiment. It is an external appearance perspective view of the dielectric filter which concerns on 2nd Embodiment. It is sectional drawing of the dielectric material filter which concerns on 3rd Embodiment. It is an external appearance perspective view of the conventional dielectric resonator.

Explanation of symbols

1-dielectric block 2-resonant conductor forming hole 3-resonant conductor 4-outer conductor 5-opening portion 6-input / output electrode 7-floating electrode portion 8-corner 9-corner 10-laser reflection point 11-laser reflector 12 -Laser processing point 13-Laser generator 14-Coupling electrode 15-Floating electrode insulator 16-Dielectric filter 17-Dielectric resonator

Claims (6)

A resonant conductor forming hole having a resonant conductor 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 an end of the resonant conductor is formed in the vicinity of at least one opening of the resonant conductor forming hole. In a dielectric resonator provided with an open part adjacent to the part and having the open end as an end ,
Wherein the floating electrode unit electrically insulated from the resonance conductor, a floating electrode insulating portion formed orbiting the該浮-out electrode portion and is surrounded by said resonant conductor and the opening portion,
A dielectric resonator in which the open portion and the floating electrode insulating portion share a part thereof . A resonant conductor forming hole having a resonant conductor 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 an end of the resonant conductor is formed in the vicinity of at least one opening of the resonant conductor forming hole. In a dielectric resonator provided with an open part adjacent to the part and having the open end as an end ,
A floating electrode portion electrically insulated from said resonant conductor, a floating electrode insulating portion formed orbiting the該浮-out electrode portion, is surrounded by resonant conductor near the open portion,
A dielectric resonator in which the open portion and the floating electrode insulating portion are separately formed . 3. The dielectric resonator according to claim 1, wherein two or more floating electrode portions are provided in the vicinity of the open portion provided in one of the resonance conductor forming holes. A dielectric filter comprising the dielectric resonator according to claim 1 and input / output means coupled to the dielectric resonator. It is a manufacturing method of the dielectric filter according to claim 4 ,
A dielectric filter characterized in that, by forming the floating electrode insulating portion in a region where the resonant conductor is formed, a filter characteristic is determined by a resonant conductor removing step in which the floating electrode portion is provided separately from the resonant conductor. Manufacturing method. The method for manufacturing a dielectric filter according to claim 5 , wherein the resonant conductor removing step is a step of removing a conductor by laser processing of the floating electrode insulating portion.

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