JPH0653717A - Dielectric resonator and dielectric filter - Google Patents

Abstract

PURPOSE:To realize the miniaturization and light weight of the dielectric resonator and the dielectric filter and to facilitate the manufacture with respect to the dielectric resonator and the dielectric filter. CONSTITUTION:The dielectric resonator is a dielectric resonator in which a resonance conductor is set to a laminator formed by laminating plural dielectric layers. The plural dielectric layers consist of low dielectric layers (dielectric constant epsilon2) made of resin and high dielectric layers (dielectric constant epsilon1) made of ceramic (epsilon1>epsilon2) and both sides (both sides in the lamination direction) of a resonance conductor 4 are inserted between the high dielectric layers 10-1 and 10-2 made of a ceramics. Then the layers 10-1, 10-2 are inserted between the low dielectric layers 9-1, 9-2 made of a resin, and the layers 9-1, 9-2 are inserted between GND electrodes 3 in the laminating direction. Furthermore, the resonance conductor 4 is made of plural resonance conductors whose resonance frequency is different and used for the dielectric filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator and a dielectric filter which can be used in various radio equipments or other communication equipments.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional example.
9A is an exploded perspective view of the dielectric filter, and FIG. 9B is a perspective view of the dielectric filter (an external view of a completed product). In FIG. 9, 1-
1 to 1-4 are dielectric layers, 3 is a GND electrode, 4-1 to 4-
4 is a resonance conductor (resonance electrode), 5 is an input terminal (IN), 6
Indicates an output terminal (OUT), and 7 indicates a margin (a portion where a conductor is not formed).

Conventionally, as a dielectric filter using a dielectric resonator, a dielectric filter using a ceramic dielectric has been proposed. An example thereof is shown in FIG. This dielectric filter is manufactured by using the lamination technique of ceramic multilayer substrates.
This is an example using the fourth dielectric layers 1-1 to 1-4.

As shown in FIG. 9A, the first dielectric layer 1
-1, the GND electrode 3 is formed, and the third dielectric layer 1 is formed.
-4, four resonance conductors (resonance electrodes of λ / 4 type resonator) 4-1 to 4-4 are formed, and on the lower side (outside) of the fourth dielectric layer 1-4. , GND electrode 3 is formed.

The first to fourth dielectric layers 1-1 to 1-1
After stacking -4, the GND electrode 3 is formed on all surfaces except one surface of the stacked body, as shown in FIG. 9B. Also, G
On one surface of the laminated body on which the ND electrode 3 is not provided, the input terminal (I
N) 5 and an output terminal (OUT) 6 are provided. in this case,
Since the input terminal 5 and the output terminal 6 need to be separated from the GND electrode 3, a margin 7 is provided between them.
Thus, the dielectric filter using the ceramic dielectric is obtained.

[0006]

SUMMARY OF THE INVENTION The above-mentioned conventional devices have the following problems. (1), a dielectric resonator using a ceramic dielectric,
When manufacturing a dielectric filter, a firing process is required. For this reason, particularly thick ones require time and effort for debinding.

(2) The dielectric resonator using the ceramic dielectric and the dielectric filter are parts that are heavier than other circuit parts. (3) It is difficult to reduce the size (especially in the thickness direction) without reducing the Q of the resonator.

In order to address these problems, it has been considered to arrange a high dielectric material around the resonance conductor and a low dielectric material outside the resonance conductor. In this case, the combinations of the high-dielectric and the low-dielectric which have been considered are as follows.

The high dielectric material is ceramic and the low dielectric material is ceramic. : High dielectric material is ceramic + resin and low dielectric material is resin. : High dielectric material is resin and low dielectric material is resin.

However, a combination of such a high dielectric material and a low dielectric material causes the following new problems. (1) In the above combination, it is necessary to stack different types of green sheets and fire them simultaneously. In this case, it is difficult to control firing because the shrinkage rates of the materials are different.

(2) In the above combination, the following is obtained. That is, since a resin generally has a low dielectric constant, a resin in which ceramic powder is dispersed is used as a high dielectric material.

However, even if such a material is used, the dielectric constant is lower than in the case of. Therefore, the wavelength cannot be sufficiently shortened. (3) In the above combination, the following is performed. That is, since a resin generally has a low dielectric constant, it is not suitable as a high dielectric constant material.

An object of the present invention is to solve the above-mentioned problems, to realize miniaturization and weight reduction of a resonator and a filter, and to facilitate manufacturing.

[0014]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, the same parts as those in FIG. 9 are designated by the same reference numerals. Further, 4 is a resonance conductor, 9-1 and 9-2 are low dielectric layers (resin), 10-1 and 10-2 are high dielectric layers (ceramics).

In order to solve the above problems, the present invention has the following configuration. (1) A dielectric resonator in which a resonance conductor is set in a laminated body in which a plurality of dielectric layers are laminated, wherein the plurality of dielectric layers are a low dielectric layer of resin (dielectric constant ε ₂ ). , A ceramic high dielectric layer (dielectric constant ε ₁ ) (provided that ε ₁
> Ε ₂ ) and both sides of the resonance conductor 4 (both sides in the stacking direction) are sandwiched by ceramic high-dielectric layers 10-1 and 10-2, and both sides (both sides in the stacking direction) are made of a resin low-dielectric layer. 9-
The layers were laminated so as to be sandwiched between 1 and 9-2, and the GND electrodes 3 were set on both sides (both sides in the lamination direction) of the layers.

(2) A dielectric filter in which a plurality of resonance conductors having different resonance frequencies are set in a laminated body in which a plurality of dielectric layers are laminated, wherein the plurality of dielectric layers are made of a resin low dielectric material. Layer (dielectric constant ε ₂ ) and ceramic high-dielectric layer (dielectric constant ε ₁ ) (provided that ε ₁ > ε ₂ ) and both sides of multiple resonance conductors with different resonance frequencies (both sides in the stacking direction) ) Is the high dielectric layer 10-1 of ceramics, 10-2
And the both sides (both sides in the stacking direction) are sandwiched between the low dielectric layers 9-1 and 9-2 made of resin, and
Further, on both sides (both sides in the stacking direction) of the GND electrodes (3)
It was set.

[0017]

The operation of the present invention based on the above configuration will be described with reference to FIG. In a resonator such as a dielectric resonator, the unloaded Q (which is referred to as Qu) is generally defined by the following equation.

[0018]

[Equation 1]

However, Qc is Q and Qd due to the transmission line conductor.
Indicates a Q due to a dielectric material, and Qr indicates a Q due to radiation. By the way, in a coaxial type resonator, 1 / Qr is usually ignored, so the equation is as follows.

[0020]

[Equation 2]

Here, Qc is expressed by the following equation by the series resistance component r _S of the transmission line conductor and the line impedance Z ₀ of the transmission line.

[0022]

[Equation 3]

Further, Qd is expressed by the following equation by the relative permittivity ε _r ′ of the dielectric material and the relative permittivity loss ε _r ″.

[0024]

[Equation 4]

From the above equation, in order to increase the unloaded Q (Qu) of the resonator, (a) increase the line impedance Z ₀ and the relative permittivity ε _r ′. (B), reducing the series resistance component r _S and the relative dielectric loss ε _r ″.

In particular, if the relative permittivity ε _r 'is increased, it goes without saying that the wavelength shortening shown by the following equation occurs.

[0027]

[Equation 5]

That is, the length of the resonance conductor of the λ / 4 type resonator is shortened by shortening the wavelength shown in the equation. Therefore, the series resistance component r _S also decreases, and both Qc and Qd increase. As a result, the no-load Q (Qu) also increases.

By the way, in the dielectric resonator and the dielectric filter of the present invention, the resonance conductor 4 or a plurality of resonance conductors having different resonance frequencies are sandwiched between the high dielectric layers 10-1 and 10-2. The wavelength shown in the formula can be shortened.

Moreover, since the low dielectric layers 9-1 and 9-2 are interposed between the high dielectric layers 10-1 and 10-2 and the GND electrode 3, the thickness in the stacking direction is reduced. However, the capacitance C component does not increase. Therefore, the line impedance Z ₀ can also be made large.

Therefore, the Q of the resonance conductor 4 which is the transmission line conductor.
(Qc) increases, and no-load Q (Qu) also increases. That is, the dielectric resonator and the dielectric filter can be downsized without reducing Q.

Further, since the high dielectric layer is made of ceramics, a firing process is required. However, it is not the conventional method of simultaneously firing different materials of a high dielectric constant material and a low dielectric constant material, but a single firing. Since one material is fired, the firing process is relatively easy.

Furthermore, since the low dielectric layer is made of resin, it does not require a firing step unlike ceramics, and can be easily manufactured by injection or the like. By using resin, a light and inexpensive dielectric resonator and , A dielectric filter can be realized.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. (1), Description of First Embodiment ... See FIGS. 2 to 6. FIGS. 2 to 6 are views showing a first embodiment of the present invention.
2 to 6, the same components as those in FIGS. 1 and 50 to 58 are designated by the same reference numerals. Further, 10B is a ceramic fired body, 11 is an external terminal (side electrode), 11 is an external terminal (side electrode), 13 is an external electrode, 14 is a metal plate, 15 is a mold, 16 is an exterior resin, and 17 is solder. Show.

The first embodiment is an example of a λ / 4 type (λ: signal wavelength) dielectric resonator, which will be described in detail below. (Description of Structure of Dielectric Resonator) See FIG. 2 FIG. 2A is a perspective view of the dielectric resonator, and FIG. 2B is a sectional view taken along line XY of FIG. 2A.

In this embodiment, a high dielectric layer made of ceramics (dielectric constant ε ₁ ) and a low dielectric layer made of resin (dielectric constant ε ₂ ) were used as the dielectric layers (provided that ε ₁ > ε). ₂ ).
As shown in the figure, this dielectric resonator is provided with a resonance conductor (resonance electrode) 4 constituting a λ / 4 type resonator at the center in the longitudinal direction.

On both sides of the resonance conductor 4 (both sides in the stacking direction of the stacked body), a ceramic high dielectric layer 10-1,
10-2 is provided, and low dielectric layers 9-1 and 9-2 made of resin are provided on both sides thereof (both sides in the laminating direction of the laminated body). In this case, it is desirable that the high dielectric layers 10-1 and 10-2 be formed thinner than the low dielectric layers 9-1 and 9-2.

Further, the above-mentioned high dielectric layers 10-1, 10-
2 and the signal input terminal portion where the GND electrode 3 is not formed and the GND electrode 3 is formed outside the signal input terminal portion outside the laminated body including the low dielectric layer 9-1 and 9-2, The external terminal 11 is formed and connected to the internal resonance conductor 4.

In this case, a blank space (a portion where the conductor is not provided) 7 is provided between the external terminal 11 and the GND electrode 3,
The external electrode 11 and the GND electrode 3 are prevented from contacting each other. With such a configuration, the dielectric resonator is an SMD (surface mount component).

(Description of Method for Manufacturing Dielectric Resonator)
3 to 6 FIGS. 3 to 6 are views for explaining the manufacturing process of the dielectric resonator according to the first embodiment. Hereinafter, the manufacturing method of the dielectric resonator will be described with reference to these drawings. In addition, S1 of FIG.
S7 shows a process number (process number for explanation) of each manufacturing process.

Step S1 ... See FIGS. 3 and 4A First, ceramic powder and a binder are mixed to form a slurry, which is applied onto a polyester film to produce a green sheet. That is, the green sheets forming the high dielectric layers 10-1 and 10-2 shown in FIG. 2 are produced.

Step S2 ... See FIGS. 3 and 4A In this step, the resonance conductor 4 is formed by depositing a conductor paste on the green sheet by thick film printing.

Step S3 ... See FIGS. 3 and 4B In this step, the green sheet is laminated with another green sheet so that the resonance conductor 4 is sandwiched therebetween, and hot pressed to obtain a laminated body.

Step S4: FIG. 3, FIG. 4B, FIG. 5C
Reference In this step, the above-mentioned laminated body is removed and fired to obtain a ceramic sintered body 10B. Then, the ceramic sintered body 10
The external electrode 13 is printed on the end of the B resonant conductor. Then, as shown in FIG.
Then, the metal plate 14 is soldered with high temperature solder.

Step S5 ... See FIGS. 3 and 5D. In this step, the ceramic sintered body 10B provided with the metal plate 14 is inserted into the mold 15 and, for example, by injection molding of liquid crystal polymer, Apply resin around the body. This resin is used for the low dielectric layers 9-1 and 9
It is used as -2.

In this case, in the mold 15, the metal plate 14 is used as a pillar to make the ceramic sintered body 10B float, and the surrounding area is covered with resin. : Step S6 ... See FIGS. 3 and 6E In this step, the resin portion formed in the above step, that is, the portion of the exterior resin 16 that is not plated is masked by a printing method or the like. Then, the surface of the exterior resin 16 is etched with acid or alkali.

Step S7 ... FIG. 3, FIG. 6F, FIG. 6G
Reference In this step, the surface of the exterior resin 16 is plated.
Then, as shown in FIG. 6G, the plated portion (GN
The portion to be the D electrode 3) is soldered to the metal plate 14 on the GND side of the dielectric resonator, and the metal plate 14 and the plated portion (the portion to be the GND electrode 3) are connected by the solder 17. .

In this case, since the other metal plate 14 is used as the external terminal 11, a margin (portion not provided with a conductor) 7 is formed around the metal plate 14 and the plated portion (GND electrode 3). Insulate from and.

By the above steps, the dielectric resonator of the first embodiment can be manufactured. In addition, as a manufacturing condition of the resin, a resin having good workability at 200 ° C. to 300 ° C. and a relative dielectric constant of 5 or less may be used.

Any type of resin may be used as long as it satisfies the above conditions, and examples thereof include PPS represented by epoxy resin and engineering plastic.
(Poly-phenylin-sulfide), liquid crystal polymer and the like can be applied.

(2) Description of Second Embodiment ... See FIGS. 7 and 8. FIGS. 7 and 8 are views showing a second embodiment of the present invention.
7 is an exploded perspective view of the dielectric filter, and FIG. 8 is a perspective view of the dielectric filter (A is a view from the front side, B is a view from the back side). 7 and 8, the same elements as those in FIGS. 1 to 6 and 9 are designated by the same reference numerals.

(Description of Structure of Dielectric Resonator) ... See FIGS. 7 and 8. In the second embodiment, four resonance conductors are used to form a λ / 4 type resonator.
This is an example in which a single dielectric filter (bandpass filter) is used.

As shown, the high dielectric layer (dielectric constant ε ₁ )
Four resonance conductors (resonance electrodes) 4-1 and 4-on 10-2
2, 4-3, 4-4 are formed, and the high dielectric layer 10 is formed thereon.
-1 is laminated. Then, on both sides (both sides in the stacking direction of the stacked body) of these high dielectric layers, the low dielectric layer 9-1,
9-2 is laminated, and the GND electrodes 3 are formed on both sides of the laminated layer.

In this case, the four resonance conductors 4-1 and 4-
2, 4-3, and 4-4 have different lengths and different resonance frequencies. In addition, the resonance conductor 4-1
One end of 4-4 (the end having the wider part in the figure) is the GND side, and the other end is the signal input side.

In this way, the four resonance conductors 4-1 and
Both sides of 4-2, 4-3, and 4-4 (both sides in the stacking direction of the stacked body) are sandwiched between the high-dielectric layers 10-1 and 10-2, and both sides (both sides in the stacking direction of the stacked body) are sandwiched. , The low dielectric layer 9-1,
9-2, and further, both sides (both sides in the stacking direction of the stacked body) are sandwiched by the GND electrodes 3.

The GND electrodes 3 are formed on all the remaining surfaces of the laminated body except the one surface on the signal input side, and the signal input surface has an input terminal (IN) 5 as an external side surface electrode. , The output terminal (OUT) 6 is formed.

In this case, since the input terminal 5 and the output terminal 6 are formed of a conductor having the same length as the thickness of the laminated body, a part of the GND electrode 3 around the input terminal 5 and the output terminal 6 is cut off to leave a blank (a portion without a conductor). ) 7 is formed.

By doing so, it is possible to prevent the input terminal 5 and the output terminal 6 from coming into contact with the GND electrode 3. Also,
By providing such external terminals, it is possible to realize an SMD (surface mount component) dielectric filter.

(Description of Method for Manufacturing Dielectric Filter)
-Refer to FIGS. 3 to 6 Since the dielectric filter of the second embodiment can be manufactured by the same manufacturing method (see FIGS. 3 to 6) as the dielectric resonator of the first embodiment, description thereof will be omitted. However, as the resonance conductor, it is necessary to set four resonance conductors having different resonance frequencies.

(Other Embodiments) The embodiments have been described above, but the present invention can be implemented as follows. (1), the dielectric filter of the second embodiment has four resonance conductors.
Although the number of resonance conductors used is not limited to this, an arbitrary number of resonance conductors may be used.

(2) The dielectric resonator of the above embodiment, and
The outer shape of the dielectric filter is not limited to the rectangular shape, and may be any shape.

[0062]

As described above, the present invention has the following effects. (1) A structure in which both sides of the resonance conductor are sandwiched by high-dielectric layers, both sides are sandwiched by low-dielectric layers, and both sides are sandwiched by GND electrodes. The dielectric filter can be miniaturized.

(2) Since only the high-dielectric layer is made of ceramic, the firing process is different from that in the case of simultaneous firing of different materials (simultaneous firing of high-dielectric layer and low-dielectric layer). It will be easier.

(3) Since the low-dielectric layer is made of resin, the weight of the dielectric resonator and the dielectric filter can be reduced as compared with the case where all are made of ceramic. (4) Since the high-dielectric layer is made of ceramic, the high-dielectric constant of the high-dielectric layer can be made higher than that of the resin made entirely of resin.

(5) Since the low dielectric layer is made of resin, it is possible to easily cover the high dielectric layer by injection, for example. Therefore, it becomes easy to manufacture the dielectric resonator and the dielectric filter.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing a dielectric resonator according to a first embodiment of the present invention.

FIG. 3 is an explanatory view (No. 1) of manufacturing steps of the dielectric resonator according to the first embodiment of the present invention.

FIG. 4 is an explanatory view (No. 2) of manufacturing steps of the dielectric resonator according to the first embodiment of the present invention.

FIG. 5 is an explanatory view (No. 3) of manufacturing steps of the dielectric resonator according to the first embodiment of the present invention.

FIG. 6 is an explanatory view (No. 4) of manufacturing steps of the dielectric resonator according to the first embodiment of the present invention.

FIG. 7 is an exploded perspective view of a dielectric filter according to a second embodiment of the present invention.

FIG. 8 is a perspective view of a dielectric filter according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 3 GND electrode 4 Resonant conductor 9-1, 9-2 Low dielectric layer (resin) 10-1, 10-2 High dielectric layer (ceramic)

Claims (2)

[Claims] 1. A dielectric resonator in which a resonance conductor is set in a laminated body in which a plurality of dielectric layers are laminated, wherein the plurality of dielectric layers are resin low dielectric layers (dielectric constant ε ₂ ). And a ceramic high dielectric layer (dielectric constant ε ₁ ) (provided that ε ₁ > ε ₂ ), both sides (both sides in the stacking direction) of the resonant conductor (4) are connected to the ceramic high dielectric layer ( 10-1 and 10-2), and both sides (both sides in the stacking direction) of the resin low dielectric layer (9
-1, 9-2) so as to sandwich them, and further, on both sides (both sides in the stacking direction) of the GND electrode (3).
A dielectric resonator characterized in that 2. A dielectric filter in which a plurality of resonance conductors having different resonance frequencies are set in a laminated body in which a plurality of dielectric layers are laminated, wherein the plurality of dielectric layers are resin low dielectric layers ( Dielectric constant ε ₂ ) and a ceramic high dielectric layer (dielectric constant ε ₁ ) (where ε ₁ > ε ₂ ), and a plurality of resonance conductors (4-1, 4-2) having different resonance frequencies are provided.
Both sides (4-3, 4-4) (both sides in the stacking direction) are sandwiched between high dielectric layers (10-1, 10-2) made of ceramics, and both sides (both sides in the stacking direction) have a low dielectric constant of resin. Body layer (9
-1, 9-2) so as to sandwich them, and further, on both sides (both sides in the stacking direction) of the GND electrode (3).
A dielectric filter characterized in that