JP2003273604A - Laminated dielectric filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a dispersion in production of a laminated dielectric filter in which both miniaturization and improvement of performance can be attained. <P>SOLUTION: In three resonant electrodes 16A, 16B and 16C, respective intervals d1 and d2 of adjacent resonant electrodes are not equal, respective short-circuit terminals are connected to a ground electrode 12, at least one principal face of respective electrode faces near the short-circuit terminal is connected through a via hole to the ground electrode 12. In the central resonant electrode 16B and the output side resonant electrode 16C, the area of opened terminal portions 16Ba and 16Ca is set to approximately equalize the frequency fluctuation quantities of the respective resonant electrodes 16A, 16B and 16C caused by the laminate deviation of the three resonant electrodes 16A, 16B and 16C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to several hundred MHz to several G.
TECHNICAL FIELD The present invention relates to a laminated dielectric filter that constitutes a resonance circuit in a microwave band of Hz, and particularly relates to a laminated dielectric filter that can suppress manufacturing variations and can realize miniaturization and high yield of the laminated dielectric filter. The present invention relates to a dielectric filter.

[0002]

2. Description of the Related Art Recently, with the diversification of wireless communication systems such as mobile phones, there has been an increasing demand for miniaturization and loss reduction of laminated dielectric filters.

In order to realize the miniaturization of the laminated dielectric filter, it is necessary to make the resonator (resonance electrode) small.

Therefore, conventionally, a method of adding a capacitance to the open end of the resonance electrode is generally performed. Particularly, in the laminated dielectric filter 100, as shown in FIG. 12, for example, the dielectric substrate 102 is used. For example, three resonance electrodes 104A, 104B and 1 each having the same width on the same plane inside
04C is formed, and each resonance electrode 104A, 104 is formed.
Upper and lower two inner layer ground electrodes (106A, 108A) and (106B, 108B) for B and 104C, respectively.
And (106C, 108C) are formed, and these two upper and lower inner layer ground electrodes (106A, 108A), (106C) are formed.
B, 108B) and (106C, 108C) are used to sandwich the open ends of the corresponding resonance electrodes 104A, 104B, and 104C, respectively.

By the way, in such a laminated dielectric filter 100, in order to determine the attenuation pole and the bandwidth (pass band), the open end capacitance of the resonance electrode (capacitance between the open end portion and the inner layer ground electrode). Is adjusted or a coupling electrode is formed between the resonance electrodes.

Normally, the resonance frequencies of the resonance electrodes on both sides are made substantially the same (for example, f1), and the resonance frequency of the center resonance electrode is set to a resonance frequency f2 different from the resonance frequency f1. The attenuation pole depends on the degree of coupling between the resonance electrodes, and the degree of coupling between the resonance electrodes is the inductance between the resonance electrodes and the capacitance between the resonance electrodes (the capacitance between the resonance electrode and the coupling electrode). .

[0007] With such a setting, there is a possibility that the band width may be limited. Therefore, a method of widening the bandwidth by setting different resonance frequencies for the three resonance electrodes has been proposed. This is achieved by making the open-ended capacitance of each resonant electrode different.

However, since it is necessary to change the attenuation pole in connection with the increase of the band width, the capacitance between each resonance electrode and the coupling electrode is changed, or the distance between each resonance electrode is changed. Is being considered. In addition,
Changing the distance between the resonance electrodes is described in, for example, Japanese Patent Laid-Open No. 5-251905.

[0009]

By the way, in the above-mentioned laminated dielectric filter 100, in the case of simultaneously realizing miniaturization and high performance, for example, a laminated dielectric filter 300 according to the proposed example shown in FIG. In the dielectric substrate 302, for example, three resonance electrodes 304A and 304B are provided.
And 304C to form adjacent resonant electrodes 304A and 3A.
Coupling electrodes 306 and 308 are placed between 04B and 304B and 304C, respectively.

Usually, in the case of the combline resonator, the resonators are always inductively coupled. Therefore, in the example of FIG. 13, the coupling between the resonators is made capacitive by adjusting the area of the coupling electrode or the like. For example, when the coupling capacitance between the central resonance electrode 304B and the coupling electrode 306 is increased, the inductive property is weakened, and when the coupling capacitance is further increased, the coupling changes to capacitive coupling. That is, the change to inductive or capacitive is performed by changing the resonance electrode 304 in the center.
It can be adjusted by the coupling capacitance between B and the coupling electrodes 306 and 308.

The distance d1 between the input side resonance electrode 304A and the central resonance electrode 304B is set to the output side resonance electrode 304C.
The reason why the distance d2 between the center resonance electrode 304B and the center resonance electrode 304B is made larger is to adjust the damping characteristics.

In such a laminated dielectric filter 300, when a λ / 4 resonator is used as a resonator, as shown in FIG. 13, a resonance electrode 304 constituting the resonator is formed.
Since one end (short-circuited end) of each of A, 304B, and 304C is connected to the ground electrode 310 formed on the side surface of the dielectric substrate 302, the resonator length is cut when divided into individual pieces (chip division). Determined by

In this cutting step, the inner layer earth electrode 3
When the length Lc from the end of 12 to the surface of the dielectric substrate 302 on the short-circuited end side (hereinafter referred to as the cut length) deviates from the specified length, the frequency fluctuates according to the deviation amount.

In particular, the example shown in FIG. 13 is an excellent structure that surely achieves both miniaturization and high performance.
Unlike the multilayer dielectric filter 100 according to the conventional example of
Since the input-side resonance electrode 304A and the output-side resonance electrode 304C are not formed symmetrically with respect to the central resonance electrode 304B in terms of capacitance and position, the frequency fluctuation amount due to the cutting of the dielectric substrate 302 is different for each resonator. May be different.

In this case, since the yield is reduced, it is necessary to secure a certain margin as an allowable range, and it is not possible to exhibit the superiority as a laminated dielectric filter having both capacitive coupling and inductive coupling. There is a risk.

The present invention has been made in consideration of such problems, and an object thereof is to provide a laminated dielectric filter capable of reducing manufacturing variations.

[0017]

A laminated dielectric filter according to the present invention is a laminated type in which two or more resonance electrodes are formed in a dielectric substrate formed by laminating a plurality of dielectric layers. In the dielectric filter, each of the two or more resonance electrodes has each short-circuit end connected to a ground electrode, and at least one main surface of each electrode surface near the short-circuit end is connected to a ground electrode via a connecting member. Is characterized by.

As a result, first, when the dielectric substrate is cut by individual division (chip division) at the manufacturing stage of this laminated dielectric filter, even if the cut length deviates from the prescribed length, Since the vicinity of the short-circuited end on at least one main surface of the resonance electrode is connected to the ground electrode via the connecting member, the resonator length of each resonance electrode seen from the ground electrode hardly changes regardless of the cut length. Become. Therefore, the frequency variation due to the variation of the cutting length is small.

In the above structure, the respective short-circuit ends of both main surfaces of the respective electrode surfaces may be connected to the ground electrode via a connecting member. In this case, it is possible to further suppress the frequency fluctuation due to the variation of the cutting length.

The connection member may be a via hole formed in the dielectric substrate. In this case, the vicinity of the short-circuited end of the resonance electrode formed in the dielectric substrate and the ground electrode on the surface of the dielectric substrate can be easily connected.

Further, the laminated dielectric filter according to the present invention has three or more resonance electrodes and three or more resonance electrodes in a dielectric substrate formed by laminating a plurality of dielectric layers. In a laminated dielectric filter having an open-ended side and an inner-layer ground electrode facing the open-ended side, all or some of the three or more resonant electrodes have their open-ended portions to determine a resonant frequency. A first electrode portion of
A second electrode portion for adjusting the frequency fluctuation amount.

Thus, first, in the manufacturing stage of this laminated dielectric filter, all or some of the three or more resonant electrodes have open ends so that the frequencies should be used as filters. It is conceivable to expand the width of the first electrode portion in the portion. In that case, if a stacking error occurs in the formation of the resonance electrodes, the variation amount of the open-end capacitance in each resonance electrode differs, and as a result, the frequency variation amount of each resonance electrode varies. This is because the change in the return loss waveform is large,
It may lead to deterioration of characteristics.

However, according to the present invention, since all or some of the three or more resonant electrodes have the second electrode portion for adjusting the frequency fluctuation amount at the open end portions thereof, respectively. By adjusting the width of the second electrode portion, the amount of frequency fluctuation of each resonance electrode due to the stacking displacement of the resonance electrodes becomes almost the same, and the characteristic deterioration can be suppressed.

In the above structure, the first electrode portion is located at a portion of the open end portion that is completely included in the inner layer ground electrode, and the second electrode portion is at the open end portion. It is preferable that the portion is different from the first electrode portion and is located at a portion facing the edge portion of the inner layer ground electrode.

When the inner-layer ground electrode is formed at a position facing the open end of each resonance electrode, although the pass band varies due to the stacking error, the change in the return loss waveform becomes small, and the characteristics Deterioration can be suppressed.

Further, in the laminated dielectric filter according to the present invention, three or more resonance electrodes and three or more resonance electrodes are provided in a dielectric substrate formed by laminating a plurality of dielectric layers. In a laminated dielectric filter in which a strip-shaped inner layer ground electrode facing the open end side is formed, all or some of the three or more resonant electrodes are laterally extended to the open end. It is characterized in that it has a projecting electrode portion formed as described above, and both ends of the projecting electrode portion are located at portions protruding from both edges of the inner layer ground electrode.

In this case, even if there is a misalignment of the resonance electrode with respect to the inner-layer earth electrode, the open-ended capacitance does not change at each resonance electrode, so that fluctuations in the pass band can be suppressed.

Further, the laminated dielectric filter according to the present invention has three or more resonance electrodes and three or more resonance electrodes in a dielectric substrate formed by laminating a plurality of dielectric layers. In a laminated dielectric filter having an inner layer ground electrode facing an open end side, each of the three or more resonant electrodes has a short-circuit end connected to a ground electrode, and a short circuit occurs on at least one main surface of each electrode surface. The vicinity of the end is connected to a ground electrode through a connecting member, and all or some of the resonance electrodes of the three or more resonance electrodes have open end portions and a first electrode portion for determining a resonance frequency. , And a second electrode portion for adjusting the frequency fluctuation amount.

Further, in the laminated dielectric filter according to the present invention, three or more resonant electrodes and three or more resonant electrodes are provided in a dielectric substrate formed by laminating a plurality of dielectric layers. In a laminated dielectric filter in which a strip-shaped inner layer ground electrode facing the open end side is formed, in each of the three or more resonance electrodes, each short-circuit end is connected to the ground electrode, and at least one main surface of each electrode surface. Is connected to the ground electrode via a connecting member, and all or some of the three or more resonant electrodes are laterally projecting at their open end portions. And both ends of the projecting electrode portion are located at portions protruding from both edges of the inner layer ground electrode, respectively.

In these inventions, it is possible to suppress the frequency fluctuation due to the variation of the cutting length with respect to the dielectric substrate, and to suppress the waveform change of the return loss due to the stacking deviation of the resonance electrode with respect to the inner layer ground electrode. it can.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a laminated dielectric filter according to the present invention will be described below with reference to FIGS.

First, in the laminated dielectric filter 10A according to the first embodiment, as shown in FIG. 1, a plurality of dielectric layers (S1 to S7: see FIG. 2) are laminated, fired and integrated,
Moreover, the dielectric substrate 1 having the ground electrode 12 formed on the surface thereof
4 and three resonance electrodes 16 are provided in the dielectric substrate 14.
A, 16B and 16C are formed.

On the surface of the dielectric substrate 14, the input terminal 18 is formed on one side surface and the output terminal 20 is formed on the other side surface. Areas 22 and 24 for insulation (the exposed portion of the dielectric substrate 14) are provided between the input terminal 18 and the ground electrode 12 and between the output terminal 20 and the ground electrode 12, respectively.

Three resonant electrodes 16A, 16B and 16C
When each is a resonance electrode of 1/4 wavelength, for example, as shown in FIGS. 3 and 5, the ground electrode 12 is provided on the surface of the dielectric substrate 14 where the resonance electrodes 16A, 16B, and 16C are exposed. A structure is employed in which one end (short-circuit end) of each of the resonance electrodes 16A, 16B, and 16C formed and short-circuited with the ground electrode 12.

Further, in this first embodiment, as shown in FIGS. 2 and 3, two inner layer ground electrodes 30 vertically opposed to the open ends of the three resonance electrodes 16A, 16B and 16C and 32 is formed. In this case, the open ends of the resonance electrodes 16A, 16B, and 16C are capacitively coupled to the ground electrode 12 through the inner-layer ground electrodes 30 and 32, respectively, so that the resonance electrodes 16A, 1C, and 1C.
The electrical length of 6B and 16C can be shortened.

Each of the inner-layer ground electrodes 30 and 32 is formed in a plate shape so as to include the open ends of the three resonance electrodes 16A, 16B and 16C in common, and the side surfaces of the dielectric substrate 14, particularly the three resonance electrodes 16A. , 16B and 16C are connected to the ground electrode 12 formed on the side surface facing the open ends.

Specifically, the structure of the laminated dielectric filter 10A according to the first embodiment will be described with reference to FIG. 2. First, the dielectric substrate 14 includes the first to seventh dielectric layers. It is configured by sequentially stacking S1 to S7. Each of the first to seventh dielectric layers S1 to S7 is composed of one or more layers.

3 is formed on one main surface of the fourth dielectric layer S4.
Resonant electrodes 16A, 16B and 16C are formed. Of these, a resonant electrode 16A (input side resonant electrode) adjacent to one side surface of the dielectric substrate 14 and a resonant electrode 16C (input side resonant electrode) adjacent to the other side surface of the dielectric substrate 14 are formed. Output side resonance electrode)
Has lead electrodes 33 and 34 for direct connection with the input terminal 18 and the output terminal 20 (see FIG. 1), respectively.

On one main surface of the third dielectric layer S3, an inner layer ground electrode 30 is formed in a position including each open end of the resonance electrodes 16A, 16B and 16C in plan view, and further, an output side resonance electrode. A first coupling electrode 36 for forming a capacitance is formed between 16C and the central resonance electrode 16B.

On one main surface of the fifth dielectric layer S5, an inner layer ground electrode 32 is formed in a position including each open end of the resonance electrodes 16A, 16B and 16C in plan view, and further, an input side resonance electrode. A second coupling electrode 38 for forming a capacitance is formed between 16A and the central resonance electrode 16B.

The first coupling electrode 36 is composed of a plane electrode portion 36A which is L-shaped in plan view, and a via hole 36B which electrically connects the plane electrode portion 36A and the output side resonance electrode 16C. The flat electrode portion 36A overlaps the first electrode portion 36Aa extending from above the output side resonance electrode 16C to above the central resonance electrode 16B and the central resonance electrode 16B, and along the central resonance electrode 16B. The second electrode portion 36Ab extending in the vertical direction is integrally formed.

Similarly to the first coupling electrode 36, the second coupling electrode 38 also has a planar L-shaped planar electrode portion 38.
A and a via hole 38B for electrically connecting the plane electrode portion 38A and the input side resonance electrode 16A. The plane electrode portion 38A extends from above the input side resonance electrode 16A to above the center resonance electrode 16B. The first electrode portion 38Aa that extends and the second electrode portion 38 that overlaps with the central resonance electrode 16B and that extends along the central resonance electrode 16B.
Ab is integrally formed.

In the laminated dielectric filter 10A according to the first embodiment, the resonance frequencies of the three resonance electrodes 16A, 16B and 16C are made different from each other in order to widen the bandwidth. There is. Therefore, the width of the portion (first electrode portion) completely included in the inner-layer ground electrodes 30 and 32 among the open end portions of all or some of the three resonance electrodes 16A, 16B, and 16C is expanded. I am trying to do it.

In this example, as shown in FIG. 5, the open end portions 1 of the central resonance electrode 16B and the output resonance electrode 16C are formed.
First electrode portion 16Ba1 in 6Ba and 16Ca
The widths HB1 and HC1 of 16Ca1 are expanded. In particular, the central resonance electrode 16B has a width H of the first electrode portion 16Ba1 at the open end portion 16Ba.
B1 is expanded toward the input side resonance electrode 16A, and the output side resonance electrode 16C is the first side in the open end portion 16Ca.
The width of the electrode portion 16Ca1 is expanded toward the central output terminal 20 side.

Further, in the first embodiment, the position of the attenuation pole on the frequency characteristic is adjusted according to the characteristic of the filter used. For example, an attenuation pole by inductive coupling and an attenuation pole by capacitive coupling are made to appear.

Normally, in the case of the combline resonator as in this embodiment, the resonators are always inductively coupled. Therefore,
In order to make the coupling between the resonators capacitive, a technique such as increasing the distance between the resonators or increasing the capacitance between the resonators is preferably adopted.

In the example shown in FIG. 2, the distances d1 and d between the adjacent resonance electrodes 16A and 16B and between the adjacent resonance electrodes 16B and 16C.
2 is not uniform, and the distance d1 between the input side resonance electrode 16A and the central resonance electrode 16B is set larger than the distance d2 between the central resonance electrode 16B and the output side resonance electrode 16C. This weakens the inductive coupling between the input side resonance electrode 16A and the central resonance electrode 16B, and the attenuation pole corresponding to the degree of coupling between the input side resonance electrode 16A and the central resonance electrode 16B is more than the pass band. It will appear at low frequencies.

To finely adjust the position of this attenuation pole,
This is performed by adjusting the area of the coupling electrode 38 of FIG. For example, when the coupling capacitance between the central resonance electrode 16B and the second coupling electrode 38 is increased, the attenuation pole is located at a lower frequency, and the central resonance electrode 16B and the second coupling electrode 3 are located.
When the coupling capacitance between 8 is reduced, the attenuation pole is located at a frequency closer to the pass band.

On the other hand, by reducing the distance between the center resonance electrode 16B and the output side resonance electrode 16C, the inductive coupling between the center resonance electrode 16B and the output side resonance electrode 16C is strengthened, and the center resonance electrode 16B and the center resonance electrode 16B. The attenuation pole corresponding to the coupling degree between the output side resonance electrodes 16C appears at a frequency higher than the pass band.

To finely adjust the position of this attenuation pole,
This is done by adjusting the area of the coupling electrode 36 of FIG. For example, when the coupling capacitance between the central resonance electrode 16B and the second coupling electrode 38 is increased, the attenuation pole is located at a lower frequency, and the central resonance electrode 16B and the second coupling electrode 3 are located.
When the coupling capacitance between 8 is reduced, the attenuation pole is located at a frequency closer to the pass band.

In the laminated dielectric filter 10A according to the first embodiment, as shown in FIG. 2, the resonance electrodes 16A, 16B, and 16C are provided on both main surfaces in the vicinity of the short-circuited end and above and below. The ground electrode 12 is electrically connected to each other via a via hole. Specifically, the vicinity of the short-circuited end on both main surfaces of the input side resonance electrode 16A and the upper and lower ground electrodes 12 are respectively formed in the via holes 40.
Central resonance electrode 1 connected via Aa and 40Ab
The vicinity of the short-circuited ends on both main surfaces of 6B and the upper and lower ground electrodes 12 are connected via via holes 40Ba and 40Bb, respectively, and the vicinity of the short-circuited ends on both main surfaces of the output side resonance electrode 16C and the upper and lower ground electrodes 12 are connected. Are connected via via holes 40Ca and 40Cb, respectively.

Therefore, the laminated dielectric filter 10A according to the first embodiment has the following operational effects.

First, in a general manufacturing process of a laminated dielectric filter, the dielectric substrate 14 is usually cut and divided into individual pieces (chip division). At this time, the cut length Lc ( (See FIGS. 5 and 13) deviates from the specified length, the resonator length changes according to the amount of deviation, and the resonance frequency at each resonance electrode fluctuates.

On the other hand, in the laminated dielectric filter 10A according to the first embodiment, each resonance electrode 16A,
The vicinity of the short-circuited end on both main surfaces of 16B and 16C and the upper and lower ground electrodes 12 are provided with via holes (40Aa, 40Aa,
40Ab), (40Ba, 40Bb) and (40Ca,
40Cb), the resonance electrodes 16A, 16B and 16 viewed from the ground electrode 12 are electrically connected.
The resonator length of C hardly changes regardless of the cut length Lc. Therefore, the frequency variation due to the variation of the cutting length Lc becomes small.

Here, one experimental example will be shown. This experimental example shows the frequency characteristics of the comparative example and the example when the cutting length Lc was set to 0, -30 μm, and +30 μm with respect to the specified length.

In the comparative example, in the laminated dielectric filter 10A according to the first embodiment, the resonance electrodes 16A and 1A are provided.
The embodiment has a configuration in which the vicinity of the short-circuited ends on both main surfaces of 6B and 16C and the upper and lower ground electrodes 12 are not connected.
It has the same configuration as the laminated dielectric filter 10A according to the first embodiment. The result of the comparative example is shown in FIG. 6, and the result of the example is shown in FIG.

From FIG. 6, in the comparative example, the cutting length L
When c is shifted (longer) in the + direction, the pass band is shifted to the lower frequency side than the prescribed band (see the chain line), and when the cutting length Lc is shifted (shorter) in the − direction, the pass band is defined. It can be seen that it is shifted to the higher frequency side than the band (see the broken line).

On the other hand, in the embodiment, as shown in FIG. 7, it can be seen that there is no fluctuation in the pass band even if the cutting length Lc deviates in the + direction or in the − direction, and is substantially constant.

In the above example, the three resonance electrodes 16A, 1
The case where the present invention is applied to the laminated dielectric filter having 6B and 16C is shown, but it is also applicable to a laminated dielectric filter having two resonance electrodes and a laminated dielectric filter having four or more resonance electrodes. .

Next, the laminated dielectric filter 10B according to the second embodiment will be described with reference to FIG.

As shown in FIG. 8, the laminated dielectric filter 10B according to the second embodiment has substantially the same structure as the laminated dielectric filter 10A according to the first embodiment described above. However, they differ in the following points.

That is, each open end portion of all or some of the three resonance electrodes 16A, 16B and 16C has a second electrode portion in addition to the above-mentioned first electrode portion.

Specifically, regarding the resonance electrode 16B, the open end portion 16Ba thereof is the first electrode portion 16Ba1 completely included in the inner layer ground electrodes 30 and 32,
It integrally has a second electrode portion 16Ba2 (a portion indicated by diagonal lines) facing the edge portions of the inner layer ground electrodes 30 and 32.

Regarding the resonance electrode 16C, the open end portion 16Ca thereof has inner layer ground electrodes 30 and 32.
Completely includes a first electrode portion 16Ca1 and a second electrode portion 16Ca2 (a portion indicated by diagonal lines) facing the edges of the inner-layer ground electrodes 30 and 32.

The widths HB2 and HC2 of the second electrode portions 16Ba2 and 16Ca2 are three resonance electrodes 1.
Resonant electrodes 1 associated with stacking deviations of 6A, 16B and 16C
The frequency fluctuation amounts of 6A, 16B and 16C are set to be substantially the same.

Specifically, first, as a premise, three resonance electrodes 16A, 16B and 1 are used in order to widen the band width.
The resonance frequencies of 6C are made different from each other. Therefore, the width of the first electrode portion at the open end portion of all or some of the three resonance electrodes 16A, 16B and 16C is expanded. In FIG. 8, the widths HB1 and HC1 of the first electrode portions 16Ba1 and 16Ca1 of the open end portions 16Ba and 16Ca of the central resonance electrode 16B and the output side resonance electrode 16C are expanded. Therefore, the open end capacities (capacitance between the open end and the ground electrode 12) of the resonance electrodes 16A, 16B and 16C are different from each other.

Then, each resonance electrode 16A, 16B and 1
If a stacking deviation occurs during the formation of 6C, the open-end capacitance in each of the resonance electrodes 16A, 16B, and 16C will change, but the rate of change differs for each resonance electrode.
As a result, the amount of frequency fluctuation due to the stacking deviation is different for each resonance electrode.

As an example, when attention is paid to two resonators (for example, two resonators including the input side resonance electrode 16A and the center resonance electrode 16B), one of the resonators has an impedance of 16Ω and the other resonator has an impedance of 16Ω. The impedance of the resonator is 12Ω. Stacking deviation in that case (stacking shift amount)
The resonance frequency fluctuation amount due to is different for each resonator as shown in FIG. The resonance frequency fluctuation amount of one resonator sharply changes with respect to the stacking deviation (see the straight line A), and the fluctuation is 2.5 times that of the other resonator (see the straight line B).

Therefore, when considering only the input side resonance electrode 16A and the central resonance electrode 16B, the central resonance electrode 16B
Open end portion 16 at (characteristic impedance 12Ω)
If the width HB2 of the second electrode portion 16Ba2 of Ba is made larger, as shown by the straight line C in FIG. 10, the frequency fluctuation amount of the central resonance electrode 16B becomes large, and the input side resonance electrode 16A (characteristic impedance 16Ω). Approach the frequency fluctuation amount of. As a result, although the pass band of the filter waveform shifts, the change in the return loss waveform can be reduced.

The same applies to the output side resonance electrode 16C, and the width HC2 of the second electrode portion 16Ca2 in the open end portion 16Ca is made larger to bring it closer to the frequency fluctuation amount of the input side resonance electrode 16A. It is possible to reduce the change in the return loss waveform.

In the example of FIG. 8, the first and second electrode portions 16 in the open end portion 16Ba of the central resonance electrode 16B are provided.
Ba1 and 16Ba2 are projected toward the input side resonance electrode 16A, and the open end portion 16C of the output side resonance electrode 16C is provided.
a in the first and second electrode portions 16Ca1 and 16
Ca2 is made to project toward the output terminal 20.

As described above, in the laminated dielectric filter 10B according to the second embodiment, the three resonance electrodes 1 are included.
Since each of the 6A, 16B, and 16C has a second electrode portion for adjusting the amount of frequency fluctuation at each open end portion of the resonance electrodes, it is possible to adjust the width of the second electrode portion. It is possible to make the amount of frequency variation of each resonance electrode substantially the same due to the displacement of the lamination of the resonance electrodes, and it is possible to suppress characteristic deterioration.

Next, a laminated dielectric filter 10C according to the third embodiment will be described with reference to FIG.

As shown in FIG. 11, the laminated dielectric filter 10C according to the third embodiment has the above-described second dielectric filter.
The multilayer dielectric filter 10B according to the embodiment of the present invention has substantially the same configuration, but the inner layer ground electrodes 30 and 32 are formed in a strip shape, and the central resonance electrode 16B and the output side resonance electrode 16C are Each open end part 16Ba
And 16Ca have projecting electrode parts 16Ba3 and 16Ca3 (shown by diagonal lines) formed by projecting in the lateral direction, and both ends of the projecting electrode parts 16Ba3 and 16Ca3 are respectively from both edges of the inner layer ground electrodes 30 and 32. It differs in that it is located in the protruding part. The open end portion 16Aa of the input side resonance electrode 16A is also located at a portion protruding from the end portions of the inner layer ground electrodes 30 and 32.

Open end portion 16B of the central resonance electrode 16B
The width HB1 including the protruding electrode portion 16Ba3 in a and the width HC1 including the protruding electrode portion 16Ca3 in the open end portion 16Ca of the output side resonance electrode 16C are expanded, and the lengths LB and LC of the protruding electrode portions 16Ba3 and 16Ca3 are inner layers. Width W of the ground electrodes 30 and 32
It is set larger.

Therefore, in the laminated dielectric filter 10C according to the third embodiment, the resonance electrodes 16A,
Even if there is a stacking deviation of 16B and 16C with respect to the inner-layer ground electrodes 30 and 32, the open end capacitance does not change at each of the resonance electrodes 16A, 16B and 16C, so that it is possible to reduce the waveform change of the return loss and to change the pass band. Can also be suppressed.

In the second and third embodiments described above, 3
The case of application to a laminated dielectric filter having one resonance electrode 16A, 16B, and 16C is shown.
It can also be applied to a laminated dielectric filter having one or more resonance electrodes.

In each of the above-described embodiments, the distance d1 between the input side resonance electrode 16A and the central resonance electrode 16B is set larger than the distance d2 between the output side resonance electrode 16C and the central resonance electrode 16B. And d2 may be substantially the same.

The laminated dielectric filter according to the present invention is not limited to the above-described embodiment, and it is needless to say that various structures can be adopted without departing from the gist of the present invention.

[0080]

As described above, according to the laminated dielectric filter of the present invention, it is possible to reduce manufacturing variations of the laminated dielectric filter.

[Brief description of drawings]

FIG. 1 is a perspective view showing a laminated dielectric filter according to a first embodiment.

FIG. 2 is an exploded perspective view showing the laminated dielectric filter according to the first embodiment.

FIG. 3 is a vertical cross-sectional view of the laminated dielectric filter according to the first embodiment, taken along the center line of the central resonance electrode.

FIG. 4 is a vertical cross-sectional view of the multilayer dielectric filter according to the first embodiment, taken along the line from the input terminal to the output terminal.

FIG. 5 is an explanatory view showing the laminated dielectric filter according to the first embodiment as viewed from above.

FIG. 6 is a diagram showing frequency characteristics when a cutting length is set to 0, −30 μm, and +30 μm with respect to a specified length in a comparative example.

FIG. 7 is a diagram showing frequency characteristics when the cutting length was set to 0, −30 μm, and +30 μm with respect to the specified length in the example.

FIG. 8 is an explanatory view showing a laminated dielectric filter according to a second embodiment as viewed from above.

FIG. 9 is a diagram showing a change in resonance frequency fluctuation amount with respect to stacking deviation between a resonator having a characteristic impedance of 16Ω and a resonator having a characteristic impedance of 12Ω.

FIG. 10 is a diagram showing an example in which a change in the resonance frequency fluctuation amount due to a stacking deviation of a resonator having a characteristic impedance of 12Ω is improved.

FIG. 11 is an explanatory view showing a laminated dielectric filter according to a third embodiment as viewed from above.

FIG. 12 is an exploded perspective view showing a laminated dielectric filter according to a conventional example.

FIG. 13 is an explanatory diagram showing a multilayer dielectric filter according to a proposed example when seen from a plane.

[Explanation of symbols]

10A, 10B, 10C ... Multilayer dielectric filter 12 ... Ground electrode 14 ... Dielectric substrate 16A ... Input side resonance electrode 16B ... Central resonance electrode 16C ... Output side resonance electrode 30, 32
... Inner layer ground electrode 36 ... First coupling electrode 38 ... Second
Coupling electrodes 40Aa, 40Ab, 40Ba, 40Bb, 40Ca,
40 Cb ... Beer hole

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01P 7/08 H01P 7/08 (72) Inventor Tainobu Osaka 2 56, Suda-cho, Mizuho-ku, Nagoya-shi, Aichi prefecture Issue Nihon Insulator Co., Ltd. (72) Inventor Takami Hirai No. 56 Suda-cho, Mizuho-ku, Nagoya-shi, Aichi Prefecture (72) Inventor Hironobu Kimura 664-1 Sarukubo, Saku-shi, Nagano Prefecture Shin Denki Co., Ltd. Chikuma Factory F-term (reference) 5J006 HA35 HB04 HB05 HB13 HB21 HB22 JA01 JA11 LA09 LA11 LA12 LA26 LA28 MA03 NA03 NB07 NC03

Claims (8)

[Claims] 1. A laminated dielectric filter in which two or more resonant electrodes are formed in a dielectric substrate formed by laminating a plurality of dielectric layers, wherein the two or more resonant electrodes are each A laminated dielectric filter, wherein a short-circuit end is connected to a ground electrode, and at least one main surface of each electrode surface is connected to the ground electrode via a connecting member in the vicinity of the short-circuit end. 2. The laminated dielectric filter according to claim 1, wherein the respective short-circuit ends of both main surfaces of each electrode surface are connected to a ground electrode through a connecting member. Type dielectric filter. 3. The laminated dielectric filter according to claim 1, wherein the connecting member is a via hole formed in the dielectric substrate. 4. A dielectric substrate formed by laminating a plurality of dielectric layers, wherein three or more resonant electrodes and an inner-layer ground electrode facing the open end side of the three or more resonant electrodes are provided. In the formed laminated dielectric filter, all or some of the resonance electrodes of the three or more resonance electrodes each have an open end portion, a first electrode portion for determining a resonance frequency, and a frequency variation amount. And a second electrode portion for adjusting the above. 5. The multilayer dielectric filter according to claim 4, wherein the first electrode portion is located in a portion of the open end portion which is completely included in the inner layer ground electrode, Of the open end portion is different from the first electrode portion and is located at a portion facing the edge portion of the inner layer ground electrode, the multilayer dielectric filter. . 6. A dielectric substrate formed by laminating a plurality of dielectric layers, and three or more resonance electrodes, and a strip-shaped inner layer ground electrode facing the open end side of the three or more resonance electrodes. In the laminated dielectric filter having and, all or a part of the resonance electrodes of the three or more resonance electrodes each have an overhanging electrode portion laterally overhanging at an open end portion, A laminated dielectric filter, wherein both ends of the projecting electrode portion are located at portions protruding from both edge portions of the inner layer ground electrode, respectively. 7. A dielectric substrate formed by laminating a plurality of dielectric layers, wherein three or more resonance electrodes and an inner layer ground electrode facing the open end side of the three or more resonance electrodes are provided. In the formed multilayer dielectric filter, each of the three or more resonance electrodes has a short-circuit end connected to a ground electrode, and at least one main surface of each electrode surface is near the short-circuit end to a ground electrode via a connecting member. All or some of the three or more resonance electrodes connected to each other have open end portions each having a first electrode portion for determining a resonance frequency and a second electrode portion for adjusting a frequency variation amount. And an electrode part of the laminated dielectric filter. 8. A dielectric substrate formed by laminating a plurality of dielectric layers, and three or more resonance electrodes, and a strip-shaped inner-layer earth electrode facing the open end sides of the three or more resonance electrodes. In the multi-layered dielectric filter formed with and, each of the three or more resonance electrodes has a short-circuit end connected to a ground electrode, and at least one main surface of each electrode surface is grounded near a short-circuit end via a connecting member. All or some of the three or more resonant electrodes connected to the electrodes have protruding electrode portions formed by laterally protruding at the open end portions, and both ends of the protruding electrode portions are A laminated dielectric filter, wherein the laminated dielectric filter is located at portions protruding from both edges of the inner layer ground electrode.