JPH09205306A - Microwave circuit element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent exfolication of a strip line by selecting a dielectric constant of a center dielectric material and an inner dielectric material almost the same and the dielectric constant of each dielectric of the inner dielectric material and an outer dielectric material different so as to make a microwave circuit element small. SOLUTION: A sintered body formed by a plate like center dielectric material 2 on which a strip line of a length of λ/4 is formed on both sides, an inner dielectric material 7 provided on both sides of the center dielectric material 2 and coating at least a strip line 6, and an outer dielectric material 3 provided onto the inner dielectric material 7 through pressing and sintering is provided and an earth electrode 4 and a terminal electrode 5 are formed on an outer information face of the sintered body. Dielectric constants A, B of the center dielectric material 2 and the inner dielectric material 7 are selected nearly the same and dielectric constants B, C of the center dielectric material 2 and the outer dielectric material 3 are selected different. Even when the interval between the strip line 6 and the earth electrode 4 is made barrow, a prescribed impedance is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave circuit element, and more particularly to a microwave circuit element formed by providing a strip line on a dielectric.

[0002]

2. Description of the Related Art Conventionally, a circuit element of this type is constructed by forming a strip line on a dielectric material having a certain dielectric constant, and further stacking the dielectric material and providing a ground electrode. In this case, the length of the strip line is selected to be λ / 4 length, where λ is the wavelength of the target microwave. Then, this λ / 4 is determined as 1 / (ε ^1/2 ) by the dielectric constant ε of the dielectric. Therefore, in order to form the microwave circuit element in a small size, a dielectric having a large dielectric constant ε is used.

[0003]

However, when a dielectric having a large dielectric constant ε is used, it is necessary to widen the distance from the ground electrode in order to prevent the impedance of the strip line from being lowered. To do this, it is necessary to increase the thickness of the dielectric that is stacked on the strip line,
As a result, the thickness of the circuit element also increases, and even if a dielectric having a large dielectric constant ε is used, it is not always possible to reduce the size.

The present invention has been made in view of the above points, and an object of the present invention is to provide a microwave circuit element which can be made thin not only in length but also in thickness.

[0005]

In order to achieve the above object, the microwave circuit element of the present invention has a strip line of λ / 4 length provided on a dielectric substrate, and further has another dielectric layer stacked thereon. In a microwave circuit element in which a ground electrode is provided on another dielectric, the dielectric constant of the portion in contact with the strip line and the dielectric constant of the other portion are different, and particularly the dielectric of the other portion. It is characterized by a low dielectric constant.

According to the above structure, the dielectric material in contact with the strip line has a dielectric constant effective for properly selecting the length of the strip line. As the dielectric to be stacked on the strip line, a dielectric having an effective permittivity for properly selecting the thickness of the circuit element is used. As described above, the length of the strip line and the thickness of the circuit element in the microwave circuit element are individually separated and an appropriate dielectric material is selected for each, so that the microwave circuit element can be downsized.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows an example of a directional coupler. The directional coupler 1 has a flat central dielectric 2
And outer dielectrics 3 and 3 provided on both sides in the thickness direction of the central dielectric 2, and a ground electrode 4 and a terminal electrode 5 are formed on the outer peripheral surface thereof. Both of the dielectrics 2 and 3 are formed in a predetermined shape and thickness according to the performance of the directional coupler 1, and both sides of the central dielectric 2 in the thickness direction have a predetermined shape so as to overlap each other. Strip lines 6 are formed respectively. The strip line 6 has its end connected to the terminal electrode 5, and the ground electrode 4 is provided on substantially the entire surface of the directional coupler 1 while being insulated from the terminal electrode 5.

Then, as shown in FIGS. 2 and 3, the dielectric constant of the portion of the dielectric A in contact with the strip line 6 is different from that of the dielectric B of the other portion. The magnitudes of the dielectric constants of the two dielectrics A and B can be appropriately set according to the performance and size required for the directional coupler 1, but normally, the dielectric constant of the dielectric B is set to the dielectric constant of the dielectric A. Make it smaller than the rate.

That is, by using a dielectric having a large dielectric constant as the dielectric A in the portion in contact with the strip line 6, the length of the strip line 6 can be shortened, and the dielectric B in the other portion can be made to have a dielectric constant. By using a material having a small ratio, a predetermined impedance can be obtained even if the distance between the ground electrode 4 and the earth electrode 4 is narrowed. As a result, the directional coupler 1 can be downsized.

The size of the dielectric A can be appropriately selected according to the required performance, the degree of manufacturing difficulty, and the like.
As shown in FIG. 3, only the central portion in contact with the strip line 6 may be provided, or sheet-like products may be stacked as shown in FIG. Further, in addition to the triplate structure in which the ground electrodes 4 are provided on the upper and lower sides as described above, a microstrip line structure in which the ground electrodes are provided only on the lower surface can be applied.

Furthermore, as the dielectrics A and B, a green sheet substrate made of a mixture of an inorganic material powder such as ceramic powder and an organic binder is used, which are laminated, sintered under pressure, and integrally fired. As a result, it is possible to prevent a gap from being formed between the dielectrics and improve the moisture resistance.

[0013]

As described above, in the microwave circuit element of the present invention, the dielectrics in contact with the strip lines and the dielectrics for providing the ground electrode overlying the strips have different dielectric constants. Therefore, it is possible to construct a desired microwave circuit element by selecting a dielectric that is suitable for the desired size, and to reduce the size and cost of various directional couplers using a stripline of λ / 4 length. Can be realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of a directional coupler.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Directional coupler 2 ... Central dielectric 3 ... Outer dielectric 4 ... Ground electrode 5 ... Terminal electrode 6 ... Stripline A ... Dielectric in a portion in contact with the stripline B ... Dielectric in other portion

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[Procedure amendment]

[Submission date] November 28, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document name] Statement

Title: Microwave circuit element and microwave circuit
Element manufacturing method

[Claims]

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a microwave circuit device.
And a manufacturing method thereof , in particular, a microwave circuit element constituted by providing a strip line on a dielectric and a manufacturing method thereof
About the law .

[0002]

2. Description of the Related Art Conventionally, a circuit element of this type is constructed by forming a strip line on a dielectric material having a certain dielectric constant, and further stacking the dielectric material and providing a ground electrode. In this case, the length of the strip line is selected to be λ / 4 length, where λ is the wavelength of the target microwave. And this λ / 4 length is
It is determined as 1 / (ε ^1/2 ) by the dielectric constant ε of the dielectric.
Therefore, in order to form the microwave circuit element in a small size, a dielectric having a large dielectric constant ε is used.

[0003]

However, when a dielectric having a large dielectric constant ε is used, it is necessary to widen the distance from the ground electrode in order to prevent the impedance of the strip line from being lowered. To do this, it is necessary to increase the thickness of the dielectric that is stacked on the strip line,
As a result, the thickness of the circuit element also increases, and even if a dielectric having a large dielectric constant ε is used, it is not always possible to reduce the size.

Therefore, the applicant of the present invention has found that a dielectric having a high dielectric constant is used.
A central dielectric and an outer dielectric with a low dielectric constant are available.
Then, form a stripline on the center dielectric.
After that, place outer dielectrics on both sides of the center dielectric,
Pressure bonding firing to make one fired body, and the outer peripheral surface of the fired body
The terminal electrodes and electrodes connected to the strip line.
Microwave circuit element (method
Proposal of a directional coupler (Shokaihei 2-44408)
Gazette).

In this case, the central dielectric and the outer dielectric are
During the firing, organic binder, etc. may be removed.
Therefore, so-called shrinkage occurs. Therefore, in manufacturing,
The central dielectric and stripline are
The degree (hereinafter, referred to as shrinkage rate for convenience) is almost the same.
Are selected respectively.

However, the central and outer dielectrics are
Since it is necessary to have different dielectric constants,
Are different in the shrinkage rate of the center dielectric and the outer dielectric.
In some cases. In such a case, burn the dielectric
The current situation is that the strip line, which is a conductor, peels off when it is formed.
Elephant may occur.

The present invention has been made in consideration of the above points , and it is possible to reduce the size of a microwave circuit element.
At the same time, it is possible to prevent the stripping phenomenon of the strip line.
Of microwave circuit elements and microwave circuit elements
The aim is to provide a method .

[0008]

According to the first aspect of the present invention, there is provided:
Such a microwave circuit element has a strip of λ / 4 length on both sides.
Of the central dielectric having the plines formed thereon,
Provided on both sides, at least the strip line
An inner dielectric to cover and provided on said inner dielectric
An outer dielectric, the central dielectric, the inner dielectric and
And the outer dielectric are each made of an inorganic material such as ceramic powder.
Plate-shaped material made of a mixture of powder and organic binder
Form the inner dielectric on each side of the central dielectric.
Body and the outer dielectric are laminated and pressure-bonded and fired into a single fire
The strip line on the outer peripheral surface of the fired body
Forming a terminal electrode and a ground pattern to be connected,
The dielectric constants of the central dielectric and the inner dielectric are almost the same.
And the dielectric constants of the inner dielectric and the outer dielectric
Are configured differently.

As a result, first, the center dielectric and the center
An inner dielectric provided on both sides of the dielectric and the inner dielectric
The outer dielectrics that are placed on the outside of the electric
Is it a mixture of inorganic powder such as powder and organic binder?
Is formed into a plate shape on both sides of the central dielectric.
The inner dielectric and the outer dielectric are laminated and crimped, respectively.
Since it is fired into one fired body,
The side dielectric and the outer dielectric can be made into an integral structure,
It is possible to prevent the formation of gaps between the dielectrics.

In addition, the strip is attached to the outer peripheral surface of the fired body.
Form the terminal and ground electrodes that are connected to the
Therefore, it is possible to reduce the number of parts.
Functioning as a small microwave circuit element
You.

Also, the central dielectric contacting the strip line
The dielectric constants of the body and the inner dielectric are almost the same, and the inner dielectric
The dielectric constants of the electric body and the outer dielectric are different.
Therefore, the dielectric constant of the center dielectric and the inner dielectric is high, and
It is possible to reduce the dielectric constant of the side dielectric. The result
As a result, in order to achieve miniaturization of microwave circuit elements,
Even if the dielectric constant of the core dielectric and the inner dielectric is increased,
This may cause a drop in stripline impedance.
Since there is no gap between the strip line and the ground electrode,
This eliminates the need to increase the thickness of the outer dielectric,
To further promote miniaturization of microwave circuit elements
it can.

In addition, the degree of coupling of the microwave circuit element is small.
If you want to increase the setting, the opposite setting, that is, the central dielectric
And lower the dielectric constant of the inner dielectric and lower the dielectric constant of the outer dielectric.
Should be higher.

Further , each of the dielectrics is exposed to heat during the subsequent firing.
Since the organic binder etc. are blown off,
Although shrinkage occurs, in the present invention, the strip that is a conductor is used.
Central dielectric on which the plane is formed and the strip line
The inner dielectrics that cover the
Since it is possible to select the material to be used,
The stripping phenomenon of the strip line will not occur.

Thus, the microwave circuit according to the present invention
As for the device, the microwave circuit device should be downsized.
It is possible to prevent strip line peeling phenomenon
can do.

Next, the microphone according to the present invention according to claim 2
The manufacturing method of the microwave circuit element is made of an inorganic material such as ceramic powder.
Specified with a material consisting of a mixture of powder and organic binder
A plate-shaped central dielectric having a dielectric constant of
A plate-shaped inner dielectric having substantially the same dielectric constant and the inner dielectric
A plate-shaped outer dielectric having a dielectric constant different from that of the electric
Dielectric fabrication process for each, and both sides of the central dielectric
Stripper that forms a λ / 4-length stripline on the
An in-formation step and at least a front surface of both sides of the central dielectric.
The inner dielectric to cover the stripline.
After arranging, the outer surface of each inner dielectric is attached to the outer surface.
A laminate manufacturing step of arranging electric bodies to manufacture a laminate, and
A fired body in which a laminated body is pressure-bonded and fired to produce one fired body
The manufacturing process and the strip line on the outer peripheral surface of the fired body.
The terminal electrode and ground pattern that are connected to the
And an electrode forming step.

Therefore, for example, first, in the dielectric manufacturing process,
Inorganic powder such as ceramic powder and organic binder
A material consisting of a mixture of
Each electrical body is manufactured and the next stripline forming process is performed.
Λ / 4 length strips on both sides of the central dielectric
A line is formed. After that, in the laminated body manufacturing process,
At least the stripline is covered on both sides of the dielectric.
After the inner dielectric is placed to cover,
The outer dielectric is disposed on each end face of the electric body.
A laminated body is produced by. After that, in the firing body manufacturing process
Then, the laminated body is pressure-bonded and fired to produce one fired body.
It is. In this case, the central dielectric, the inner dielectric and the outer dielectric
The body can be made into an integral structure, and the gap between each dielectric is generated.
Life can be prevented.

After the production of the fired body, the next electrode forming step is performed.
Connect to the strip line on the outer peripheral surface of the fired body
A terminal electrode and a ground electrode are formed. This place
In this case, it is possible to reduce the number of parts
It can be a microwave circuit element.

Also, the central dielectric contacting the strip line
The dielectric constants of the body and the inner dielectric are almost the same, and the inner dielectric
The dielectric constants of the electric body and the outer dielectric are different.
Therefore, the dielectric constant of the center dielectric and the inner dielectric is high, and
It is possible to reduce the dielectric constant of the side dielectric. The result
As a result, in order to achieve miniaturization of microwave circuit elements,
Even if the dielectric constant of the core dielectric and the inner dielectric is increased,
This may cause a drop in stripline impedance.
Since there is no gap between the strip line and the ground electrode,
This eliminates the need to increase the thickness of the outer dielectric,
To further promote miniaturization of microwave circuit elements
it can.

The degree of coupling of the microwave circuit element is small.
If you want to increase the setting, the opposite setting, that is, the central dielectric
And lower the dielectric constant of the inner dielectric and lower the dielectric constant of the outer dielectric.
Should be higher.

Further , in the present invention, a strip which is a conductor
The central dielectric on which the line is formed and the strip line
The shrinkage rates of both inner dielectrics are almost the same.
Since the material can be selected,
Stripping of the stripline does not occur.

Thus, the microwave circuit according to the present invention
In the device manufacturing method, the size of the microwave circuit device is small.
And strip line stripping
The phenomenon can be prevented.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The microwave circuit according to the present invention will be described below.
Example of embodiment in which a path element is applied to a directional coupler (hereinafter,
(Simply referred to as a microwave circuit element according to the embodiment)
This will be described with reference to FIGS.

Microwave circuit element 1 according to the present embodiment
As shown in Fig. 1, both sides are λ / 4 length strippers.
A plate-shaped central dielectric 2 having the ins 6 formed thereon, and the central dielectric 2.
Provided on both sides of the electric body 2 and at least the strip
An inner dielectric 7 covering the line 6 (see FIG. 2), and
The outer dielectric 3 provided on the side dielectric 7 is pressed and baked.
And a ground electrode 4 and a terminal electrode 5 are formed on the outer peripheral surface of the fired body .

Specifically, the micro according to the present embodiment
The wave circuit element 1 has an inorganic material powder such as ceramic powder or the like.
With a green sheet made of a mixture with machine binder
The central dielectric 2 that will be the formed coupling layer and the ceramic
Mixture of inorganic material powder such as powder and organic binder
Is formed by a green sheet consisting of
To cover both sides of body 2, especially stripline 6
A pair of inner dielectrics 7 and ceramic powder
It consists of a mixture of powdered inorganic material powder and organic binder.
Each of the inner dielectrics 7 formed by a green sheet
And an outer dielectric 3 provided thereon
You.

Central dielectric 2, inner dielectric 7 and outer dielectric
The body 3 depends on the performance of the microwave circuit element 1, respectively.
It is formed in a predetermined shape and thickness,
Predetermined shape on both sides in the thickness direction so that they overlap each other
Λ / 4 strip lines 6 are formed respectively
I have. Each strip line 6 is connected to the front through the extraction electrode.
The wiring is formed so as to be connected to the terminal electrode 5.

The central dielectrics 2 and 2 thus formed
The inner dielectric 7 and the two outer dielectrics 3 are
Inner dielectrics 7 are laminated with the central dielectric 2 sandwiched therebetween,
Next, the two outer dielectrics 3 and the central dielectric 2 and the inner
To be laminated with a laminate consisting of the dielectric 7 sandwiched between them.
Therefore, a laminated body having a five-layer structure is produced as a whole.

Then, the laminated body of this five-layer structure is in a crimped state.
The central dielectric 2, the inner dielectric 7 and the outer dielectric are fired in the state.
The electric body 3 is integrated into a fired body having an integrated structure. this
Therefore, each of the central dielectric 2, the inner dielectric 7, and the outer dielectric 3 is
It is possible to prevent the formation of gaps between each other,
Performance can be improved.

Then, the stripes are formed on the outer peripheral surface of the fired body.
Terminal electrode 5 and ground electrode 4 connected to the up line 6
And the microwave circuit element according to the present embodiment is formed.
1 is produced. The earth electrode 4 is isolated from the terminal electrode 5.
Formed on almost the entire surface of microwave circuit element 1 in a rimmed state
Is done.

Further, the microwave circuit according to the present embodiment
In the element 1, the central dielectric 2 and the inner dielectric 7 are mutually
The dielectric constants A and B are set to be almost the same, and
The electric conductor 7 and the outer dielectric 3 have different dielectric constants B and C from each other.
Is set to.

Central dielectric 2, inner dielectric 7 and outer dielectric
The relationship between the dielectric constants A, B and C of the body 3 is microwave.
Set appropriately according to the performance and size required for the circuit element 1.
However, in this example, the dielectric constant of the outer dielectric 3 is
C is set smaller than the dielectric constant B of the inner dielectric 7.
You.

By setting in this way, the central dielectric
Since the body 2 having a high dielectric constant A is used,
The length of the lip line 6 can be made short and the outside
Since the dielectric material 3 having a low dielectric constant C is used,
Narrow the distance between the strip line 6 and the ground electrode 4
Can also obtain a predetermined impedance. others
Therefore, the microwave circuit element 1 can be downsized.
You.

In addition, an inorganic material powder such as ceramic powder
With a green sheet made of a mixture with an organic binder
Central Dielectric 2, Inner Dielectric 7 and Outer Dielectric Formed
No. 3 shows that the organic binder and the like do not fly during the subsequent firing.
So-called shrinkage occurs due to the fact that
In the embodiment, the strip line 6 which is a conductor is formed.
Of the central dielectric 2 and the strip line 6
Set the dielectric constants of the side dielectrics 7 to be substantially the same.
Therefore, as the central dielectric 2 and the inner dielectric 7,
It is possible to select materials that both have the same shrinkage rate.
It is possible to remove the strip line 6 during the firing.
Elephants will not occur.

The size of the inner dielectric 7 is required.
It can be appropriately selected according to the performance and the difficulty of manufacturing,
As shown in FIG. 2, it is the central part that contacts the strip line 6.
It may be used as a tray, and as shown in Fig.
You may make it layer. Also, as described above,
In addition to the triplate configuration with the base electrode 4, only on the lower surface
Of the microstrip line configuration with the ground electrode 4
It can also be applied to things.

[0034]

As described above, the book according to claim 1 is described.
According to the microwave circuit element of the present invention, λ / 4 is provided on both surfaces.
A central dielectric having a long stripline formed,
Provided on both sides of the central dielectric, and at least the stripes
An inner dielectric covering the spline and on the inner dielectric
And an outer dielectric provided on the central dielectric,
Ceramic powder for the inner and outer dielectrics
Consisting of a mixture of inorganic material powder such as
Formed in a plate shape with material, on each side of the central dielectric
The inner dielectric and the outer dielectric are laminated and pressure-bonded and fired.
As one fired body, and the strip is attached to the outer peripheral surface of the fired body.
The terminal electrode and ground pattern connected to the
And the respective dielectric constants of the central dielectric and the inner dielectric are formed.
Almost the same, and the inner dielectric and the outer dielectric
Each of the dielectric constants is different.

Therefore, miniaturization of the microwave circuit element is required.
The stripping phenomenon of stripline
The effect that can be prevented is achieved.

A microphone according to the present invention as defined in claim 2
According to the method for manufacturing a microwave circuit element, ceramic powder, etc.
Material consisting of a mixture of inorganic material powder and organic binder
A plate-shaped central dielectric having a predetermined dielectric constant with
A plate-shaped inner dielectric having substantially the same dielectric constant as the electric body;
A plate-shaped outer dielectric with a different dielectric constant from the inner dielectric
Each of the dielectric fabrication steps and the central dielectric
Strip for forming λ / 4 length stripline on both sides
Pline formation process and at least on both sides of the central dielectric
Also the inner dielectric to cover the stripline
After arranging the body,
Laminated body manufacturing process for arranging side dielectrics to manufacture a laminated body
Then, the laminated body is pressure-bonded and fired to produce one fired body.
The step of producing the fired body and the strip on the outer peripheral surface of the fired body
Form the terminal electrode and ground pattern connected to the
And a step of forming an electrode.

Therefore, miniaturization of the microwave circuit element is required.
The stripping phenomenon of stripline
The effect that can be prevented is achieved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of a microwave circuit element .

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of Codes] 1 ... Microwave circuit element 2 ... Central dielectric 3 ... Outer dielectric 4 ... Ground electrode 5 ... Terminal electrode 6 ... Strip line 7 ... Inner dielectric

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

[Fig. 2]

[Procedure 3]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

[Figure 3]

Claims (3)

[Claims] 1. A microwave circuit element comprising a dielectric substrate provided with a λ / 4-length strip line, another dielectric layer superposed thereon, and a ground electrode provided on the other dielectric layer, wherein the strip line is provided. A microwave circuit element, wherein the dielectric constant of a portion in contact with the dielectric is different from that of another portion. 2. The microwave circuit element according to claim 1, wherein the dielectric constant of the other part is smaller than the dielectric constant of the part in contact with the strip line. 3. The micro according to claim 1, wherein the dielectric is integrally fired using a green sheet substrate made of a mixture of an inorganic material powder such as ceramic powder and an organic binder. Wave circuit element.