JP3265831B2 - Non-reciprocal circuit device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quasi-microwave band, a nonreciprocal circuit device used in a microwave band, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Non-reciprocal circuit elements used in mobile communication devices such as mobile phones and automobile phones have a function of passing a signal only in the transmission direction and preventing transmission in the reverse direction. As this type of non-reciprocal circuit device, for example, a lumped-constant type circulator or isolator in which a plurality of center electrodes are arranged in an electrically insulated state and cross each other, and a magnetic material for microwaves is arranged at the cross portion. is there.

FIGS. 4 and 5 show an equivalent circuit diagram and a schematic configuration diagram of a conventional Y-type broadband circulator, respectively.
This lumped constant type circulator 1 has three center electrodes 2
Are intersected at an angle of 120 degrees with an insulator interposed therebetween, and the microwave magnetic body 3 is arranged at the intersection, and a DC magnetic field is applied to the magnetic body 3 by the permanent magnet 4. ing. One end of each of the center electrodes 2 is connected to the external conductor 5 and the other end is connected to input terminals A, B, and C, respectively. The input terminals A to C are connected to an inductance portion Ls and a capacitor portion Cs. ing.

In the circulator 1, in order to widen the center frequency, a series resonance circuit L is connected between the outer conductor 5 and a ground conductor 6 arranged in an insulated state.
w and Cw are connected, so that resonance occurs near the center frequency of the operating frequency band. Conventionally, such a resonance circuit is generally formed by forming a capacitor electrode on a dielectric substrate or the like made of barium titanate or the like and disposing the capacitor electrode between the external conductor 5 and the ground conductor 6. It is.

[0005]

In recent years, mobile communication devices have been improved in performance, downsizing, versatility, and cost reduction because of their applications. Accordingly, non-reciprocal circuit devices have been developed. Demands for higher performance, smaller size, lower cost, etc. are increasing.

In order to meet such a demand, the space between the microwave magnetic body and the permanent magnet is made as narrow as possible, so that a DC magnetic field can be efficiently applied to the magnetic body and the size can be reduced. Can contribute. However, when the space is narrowed, it becomes difficult to dispose a dielectric substrate constituting a series resonance circuit, and there is a problem that high performance and miniaturization cannot be accommodated.

In addition, when the above-mentioned series resonance circuit is added, the characteristic value is liable to change greatly depending on the position where the series resonance circuit is added. Must be added to However, since the space for adding the resonance circuit is extremely narrow as described above, it is difficult to maintain accurate symmetry, and there is a problem that high performance cannot be achieved.

Further, in the above-described conventional structure, since a separate part such as a magnetic material for microwaves and a dielectric substrate for a resonance circuit is assembled, the cost increases as the number of parts and the number of manufacturing steps increase. From the point of view, we cannot respond to the above request.

The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide a non-reciprocal circuit device capable of coping with high performance, miniaturization, and cost reduction, and a method of manufacturing the same.

[0010]

According to the first aspect of the present invention, a green body made of a magnetic material for microwaves is laminated and integrally sintered in a fired body in an electrically insulated state.
In addition, a plurality of center electrodes arranged in an intersecting manner and a capacitor electrode for taking out a capacitance for a resonance circuit are stacked and buried, and both end surfaces of each of the center electrodes and end surfaces of the capacitor electrode are led out to the outer surface of the fired body. Then, one end face of each of the center electrodes and the end face of the capacitor electrode are connected by an external extraction electrode formed on an outer surface of the fired body, and a ground electrode is formed on at least one main surface of the fired body. A resonance circuit capacitor layer made of the magnetic material for microwaves is formed between an electrode between the ground electrode and the capacitor electrode.

Here, yttrium iron garnet, calcium vanadium garnet, manganese magnesium ferrite, nickel zinc ferrite, lithium ferrite and the like can be used as the magnetic material for microwaves.

According to a second aspect of the present invention, in the first aspect, the resonance circuit capacitor is connected in series between a center axis of an external extraction electrode of each of the center electrodes and the ground electrode. And

According to a third aspect of the present invention, there is provided the method of manufacturing a non-reciprocal circuit device, wherein a first step of forming a plurality of green sheets made of a magnetic material for microwaves, and forming a central electrode on each green sheet is performed. At the same time, a capacitance electrode for taking out the resonance circuit capacitance is formed in a pattern on another green sheet, and the remaining green sheets are overlapped on the upper and lower surfaces of the green sheet on which the respective center electrodes are formed. Layered green sheets,
A second step of stacking a green sheet constituting a resonance circuit capacitance layer on a lower surface of the green sheet to form a laminate;
Forming a fired body by simultaneously firing the laminate and each of the center electrode and the capacitor electrode to form a fired body, and forming an external extraction electrode connecting one end of each of the center electrodes and the end face of the capacitor electrode to the outer surface of the fired body. And a third step of forming a ground electrode on at least one main surface of the fired body.

[0014]

According to the nonreciprocal circuit device according to the first aspect of the present invention, since the capacitor electrode for extracting the capacitance for the resonance circuit is integrally buried in the fired body made of the magnetic material for microwaves, the conventional dielectric substrate is unnecessary. Therefore, the space between the magnetic body and the permanent magnet can be narrowed accordingly. As a result, the DC magnetic field application efficiency can be improved, and higher performance and smaller size can be accommodated. Further, since the dielectric portion of the capacitor electrode is made of the same material as the magnetic material, dielectric loss in the quasi-microwave band and the microwave band can be reduced, and a high Q value resonance capacitance can be obtained. Compatible with high performance.

Further, according to the present invention, since the capacitor electrode and the capacitor layer are integrally formed in the microwave magnetic body, the conventional steps of separately forming and assembling the components can be eliminated, and the number of components and the number of manufacturing steps can be reduced. Cost can be reduced as much as possible.

According to the second aspect of the present invention, since the resonance circuit capacitor is connected in series between the center axis of the external extraction electrode of each center electrode and the ground electrode, the energy at the time of in-phase excitation can be increased efficiently. Compatible with high performance. That is, since the resonance circuit capacitor can be installed in a narrow space where the magnetic material and the permanent magnet are close to each other as described above, it is possible to add the resonance circuit to the center axis, and thus, it is possible to accurately adjust the resonance circuit with respect to the input terminal. Sex can be maintained.

According to the third aspect of the present invention, a center electrode and a capacitor electrode are formed in a pattern on a plurality of green sheets made of a magnetic material for microwaves, and the green sheets and the remaining green sheets are laminated and then integrally fired. An external electrode for connecting each center electrode and the capacitor electrode is formed on the outer surface of the fired body, and a ground electrode is formed on one main surface of the fired body. Capacity can be formed at the same time, and the cost can be reduced as described above.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views for explaining a non-reciprocal circuit device and a method for manufacturing the same according to one embodiment of the first to third aspects of the present invention. FIG. 1 is a perspective view of the non-reciprocal circuit device of the present embodiment. FIG. 2 is a schematic structural view of the device of this embodiment, and FIG. 3 is an exploded perspective view showing a manufacturing process of the device of the above embodiment. In this embodiment, a case where the present invention is applied to a lumped constant type circulator will be described as an example.

In the figure, reference numeral 10 denotes a lumped constant type circulator, which comprises a cylindrical fired body 11, which is housed in a metal yoke (not shown) constituting a magnetic closed circuit. In the fired body 11, three center electrodes 12a to 12c are buried, and the center electrodes 12a to 12c are electrically insulated from each other.
They are arranged so as to intersect at every 0 degree angle. Both end surfaces of each of the center electrodes 12a to 12c are led out to the outer peripheral surface 11a of the sintered body 11, and external lead-out electrodes 13a to 13c and 14a to 14c are connected to the lead portions. Further, both end faces 11b and 11c of the sintered body 11 are provided.
Are formed with ground electrodes 15, 15 which are grounded to a metal yoke.

The fired body 11 is formed by laminating green sheets made of a magnetic material for microwaves, which will be described later, and integrally firing the green sheets.
Permanent magnets 16, 16 are arranged close to b, 11 c, and a DC magnetic field is applied to the fired body 11 by the permanent magnets 16.

At the lower part of the fired body 11, a capacitor electrode 17 for taking out a capacitance for a series resonance circuit is embedded, and the peripheral end face of the capacitor electrode 17 is led out to the outer peripheral surface 11a of the fired body 11. The external electrodes 14a to 14c are connected to the capacitor electrode 17, and the electrode 17 also functions as an external conductor.

The capacitance electrode 17 and the center electrode 12a
Layer 1 made of a magnetic material for microwaves between
8 are formed, and the capacitance layer 18 serves as a capacitor portion Cs of the lumped constant circulator. Further, a capacitance layer 19 made of a magnetic material for microwaves is formed between the capacitance electrode 17 and the ground electrode 15, and this capacitance layer 19 becomes a series resonance circuit capacitance portion Cw that resonates near the center frequency. I have.

Next, a method of manufacturing the circulator 10 will be described. First, yttrium oxide (Y ₂ O
₃ ) A microwave magnetic powder mainly containing iron oxide (Fe ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ) is prepared, and the powder is dispersed in an organic solvent together with a polyvinyl alcohol-based binder to form a slurry. This magnetic slurry is formed into a mother sheet having a thickness of several tens of μm by a doctor blade method, and this sheet is punched into a rectangle of 40 mm × 20 mm to form a large number of magnetic green sheets for microwaves 20 to 22 (first). Process).

Next, as shown in FIG. 3, an electrode paste is prepared by mixing palladium or platinum powder and an organic solvent, and this paste is applied to the three green sheets 20.
Center electrodes 12a-1 which are screen-printed on the surface of
2c is formed. Further, an electrode paste is printed on the surface of the one green sheet 21 to form the circular capacitor electrode 17.

Each of the green sheets 20 is overlapped such that the center electrodes 12a to 12c thereof form an intersection angle of 120 degrees with each other. A green sheet 21 on which the capacitance electrode 17 is formed is further stacked on the lower surface of the lower green sheet 22 and a plurality of green sheets 22 are stacked on the lower surface of the lower green sheet 22 to form a laminate.
This laminate is pressed. This laminated body is punched into a cylindrical shape having a diameter of 10 mm to form an unfired chip (second step).

Next, the unfired chips are placed in a range of 1300 to 15
By firing at a temperature of 00 ° C., a fired body 11 is formed. The outer peripheral surface 11a of the fired body 11 is polished, and the center electrodes 12a to 12a are polished.
12c and the end face of the capacitor electrode 17 are exposed. After this,
After a metal paste containing glass frit is applied to the outer peripheral surface 11a of the fired body 11, it is baked to obtain the externally-taken electrode 1
4a to 14c are formed, one end of each of the center electrodes 12a to 12c is connected to the capacitor electrode 17, and the input terminal electrodes 13a to 13c are connected to the other end of each of the center electrodes 12a to 12c.
Is formed (third step).

Thereafter, both end faces 11 of the fired body 11 are formed.
A ground electrode 15 is formed on each of the b and 11c, and is housed in a metal yoke together with the permanent magnet 16. The matching circuit capacitor may be provided inside the fired body 11,
Further, it may be provided outside the fired body 11.

Next, the operation and effect of this embodiment will be described. According to the present embodiment, the capacitance electrode 17 is buried in the fired body 11 made of a magnetic material for microwaves to form a series resonance circuit capacitance. Therefore, the conventional dielectric substrate can be eliminated, and the fired body 11 can be used accordingly. The permanent magnets 16 can be arranged close to each other. As a result, it is possible to improve the efficiency of applying a DC magnetic field to each of the center electrodes 12a to 12c, thereby achieving high performance and downsizing. In addition, since the capacitance layers 18 and 19 of the capacitance electrode 17 are made of a microwave magnetic material, dielectric loss in the quasi-microwave band and the microwave band can be reduced, and a resonance capacitance having a high Q value can be obtained. Can respond to high performance.

Further, according to the present embodiment, each of the center electrodes 12a to 12
(c) Since the capacitor electrode 17 is formed, and these are laminated and then integrally fired to form the fired body 11, the number of parts and the number of manufacturing steps can be reduced as compared with the conventional structure, the cost can be reduced, and the yield can be improved. .

In this embodiment, since the capacitance electrode 17 is connected in series between the center axis of the center electrodes 12a to 12c and the ground electrode 15, the energy at the time of in-phase excitation can be efficiently increased, and a wider band is achieved. In this case, the symmetry can be accurately maintained, and from this point, it is possible to cope with higher performance.

In the above embodiment, a circulator has been described as an example, but the present invention can of course be applied to an isolator in which a terminal resistor is connected to one center electrode port.

[0032]

As described above, according to the non-reciprocal circuit device according to the first aspect of the present invention, the capacitance electrode for extracting the capacitance for the resonance circuit is embedded in the fired body made of the magnetic material for microwaves. Since the dielectric portion of the capacitor is constituted by the capacitor layer made of the same material as the magnetic material for microwaves, the space between the magnetic material and the permanent magnet can be reduced. In addition, the number of parts and the number of manufacturing steps can be reduced to reduce costs.

According to the second aspect of the present invention, since the resonance capacitor is connected in series between the center axis of the external extraction electrode of each center electrode and the ground electrode, accurate symmetry with respect to the input terminal is maintained. This also has the effect of being able to respond to higher performance.

According to the third aspect of the present invention, the center electrode and the capacitor electrode are formed in a pattern on a plurality of green sheets made of a magnetic material for microwaves, and the green sheets and the remaining green sheets are laminated and then integrally fired. This has the effect of reducing costs by reducing the number of parts and manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lumped constant circulator according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a circulator of the embodiment.

FIG. 3 is an exploded perspective view showing a manufacturing process of the circulator of the embodiment.

FIG. 4 is an equivalent circuit diagram of a conventional lumped constant circulator.

FIG. 5 is a schematic configuration diagram of a conventional circulator.

[Explanation of symbols]

 Reference Signs List 10 circulator (non-reciprocal circuit device) 11 fired body (magnetic material for microwave) 12a to 12c center electrode 15 earth electrode (ground conductor) 17 capacitance electrode 18, 19 capacitance layer 20 to 21 green sheet

Continuation of the front page (56) References JP-A-5-95207 (JP, A) JP-A-5-304404 (JP, A) JP-A-4-345201 (JP, A) JP-A-4-172702 (JP) JP-A-6-69057 (JP, A) JP-A-49-73053 (JP, A) JP-A-57-61314 (JP, A) JP-A-48-101061 (JP, A) 63-300594 (JP, A) Actually open 1981-123624 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01P 1/383 H01P 11/00

Claims (3)

(57) [Claims] 1. A green made of a magnetic material for microwaves.
In a fired body made by laminating and integrally sintering sheets,
Electrically insulated and crossed
Laminated core electrode and capacitance electrode for extracting resonance circuit capacitance
And buried in both ends of each of the center electrodes and the capacitance electrodes
Of the center electrode is led out to the outer surface of the fired body.
The end face and the end face of the capacitor electrode are formed on the outer surface of the fired body
Connected with the external extraction electrode
At least one main surface is formed with an earth electrode, and
The above-mentioned magnetic material for microwaves is placed between the storage electrode and the electrode.
A non-reciprocal circuit device, comprising a resonance circuit capacitor layer formed thereon. 2. The method of claim 1, capacitor the resonance circuit is, on the central axis of the external lead electrodes of the respective central electrode
A non-reciprocal circuit device, which is connected in series with the earth electrode . 3. Production of the non-reciprocal circuit device according to claim 1.
A method, a first step of forming a plurality of green sheets made of a magnetic material for microwave, the green sheets
Pattern the center electrode on the other green
Pattern the capacitance electrode to take out the resonance circuit capacitance on the sheet
Of the green sheet on which the respective center electrodes are formed.
Stack the remaining green sheets on the upper and lower surfaces, and
The green sheets on which the storage electrodes are formed are stacked, and
To form a resonance circuit capacitance layer on the lower surface of the green sheet
A second step of forming a laminate by stacking sheet sheets;
Simultaneously firing the layer body and each center electrode and capacitor electrode
A fired body is formed, and one of the center electrodes is provided on the outer surface of the fired body.
Form an external extraction electrode that connects the end to the end face of the capacitor electrode.
And a ground electrode formed on at least one main surface of the fired body.
A method for manufacturing a non-reciprocal circuit device, comprising: