JP3178153B2 - Non-reciprocal circuit element for microwave - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reciprocal circuit device for a micro device used for, for example, a circulator or an isolator, and more particularly, to a method using a magnetic material obtained by laminating a magnetic material and an electrode material and then firing them integrally. And a non-reciprocal circuit device for microwaves.

[0002]

2. Description of the Related Art In recent years, in mobile communication and the like, high-frequency devices have been reduced in size and general-purpose, and the size and cost of non-reciprocal circuit devices used have been strongly demanded.

The non-reciprocal circuit device includes, for example, a plurality of center electrodes arranged in an electrically insulated state and crossing each other, and a microwave magnetic member provided above and below the plurality of center electrodes. There is a so-called lumped-constant type non-reciprocal circuit element in which a body is arranged, and further a DC magnetic field is applied by a permanent magnet to a portion where the plurality of center electrodes intersect. Constant circulators, isolators and the like can be mentioned.

FIG. 3 is a perspective view for explaining an example of an assembling process of a conventional microwave non-reciprocal circuit device. When assembling the microwave irreversible circuit element, first, a center electrode 24a made of a metal foil, for example, a Cu foil is arranged on a disk-shaped microwave magnetic body 23a.

[0005] The center electrode 24a is made of a magnetic material 2 for microwaves.
The shape extends in the radial direction through the center of the upper surface of 3a and further reaches the side surface of the microwave magnetic body 23a. Next, an insulating film 25a made of an insulating material is disposed on the central electrode 24a, and another central electrode 24b is disposed thereon so as to cross the central electrode 24a. Further, an insulating film 25b, a center electrode 24c, and an insulating film 25c are sequentially laminated on the center electrode 24b, and the microwave magnetic body 23b
Are laminated from the top.

The microwave irreversible circuit element assembled as described above is combined with a permanent magnet, a yoke holding the permanent magnet, and the like as shown in an exploded perspective view of FIG. And was configured as an isolator.

That is, a through hole 31a for accommodating the above-mentioned non-reciprocal circuit device for microwave is formed in the center of a substrate 31 made of a rectangular insulating material such as alumina.
On the upper surface of the substrate 31, electrodes 32, 3 for extracting capacitance are provided.
2, 32 are formed by printing a conductive film.

On the other hand, a ground electrode is formed on the lower surface of the substrate 31 so as to face the electrodes 32 for taking out the capacitance and the front and back with the substrate 31 interposed therebetween. An earth plate 33 shown below is joined to this earth electrode by soldering, and the substrate 31 and the earth plate 33 are integrated. The ground plate 33 is made of a metal plate, has a through hole 33a at the center, and has rising pieces 33b, 33b at a portion facing the through hole 33a. The rising pieces 33b, 33b are projected upward through the through holes 31a of the substrate 31 in a state where the substrate 31 and the ground plate 33 are joined as described above. As is clear from FIG. 5 showing the main parts after assembly, the protruding piece 33b is provided with the center electrodes 24a to 24 of the non-reciprocal circuit element for microwave.
c is connected to one end by soldering or the like. FIG.
In the figure, the above-mentioned insulating films 25a to 25c are omitted. Reference numeral 37 in FIG. 5 indicates a ground electrode formed on the lower surface of the substrate 31. The capacitance extracting electrodes 32, 3
2, a substrate 31, and a ground electrode 37 formed on the back surface of the substrate 31 constitute a capacitance for impedance matching.

On the other hand, the other ends of the center electrodes 24a to 24c of the non-reciprocal circuit element for microwave are connected to a capacitor formed on the upper surface of the substrate 31 as shown in FIG. It is electrically connected to the extraction electrode 32. Similarly, the other ends of the other center electrodes 24a and 24b are also electrically connected to other capacitance extracting electrodes.

Returning to FIG. 4, the substrate 31 and the ground plate 33
Are laminated, the non-reciprocal circuit device for microwave is incorporated in the through holes 31a, 33b, and the non-reciprocal circuit device for microwave is configured by being sandwiched between yokes 34, 35 from above and below. On the lower surface of the yoke 34, a permanent magnet 36 is fixed. The yokes 34 and 35 are made of a metal material, and a pair of opposing edges are bent toward the other side.
Utilizing the bent portion, both are fixed by soldering or the like or by mechanical engagement.

As described above, in the conventional non-reciprocal circuit element for microwave, not only a complicated manual operation is required when assembling the structure shown in FIG. 3, but also a permanent magnet for applying a DC magnetic field. And connection of earth electrodes, etc.
Soldering and complicated manual work were forced.

As described above, in the conventional microwave non-reciprocal circuit device, an insulating resin film or a resin tape is interposed between the center electrodes in order to electrically insulate the plurality of center electrodes. The insulating substrate on which the center electrode was printed was bonded. In addition, the insulating film and the insulating substrate are usually assembled sequentially by hand. In addition, in a non-reciprocal circuit device for microwaves, it is often necessary to add a capacitance for impedance matching, but such a capacitance for a matching circuit can be obtained by connecting a separately prepared capacitor. Alternatively, as described above, a capacitor was formed using an insulating substrate, and this was performed by combining it with a non-reciprocal circuit element for microwave. However, work for configuring such an additional capacitor was also performed manually. Had been

[0013]

As described above, in the conventional non-reciprocal circuit device for microwave, not only the main part provided with a plurality of center electrodes and the magnetic material for microwave, but also
A capacitor for forming an additional capacitor for impedance matching must be assembled by a complicated manual operation, and the number of parts is very large, so that the cost is very high.

An object of the present invention is to integrally form a center electrode portion and a capacitor for impedance matching which intersect in a state of being electrically insulated from each other, and to manufacture it very easily without complicated manual work. It is another object of the present invention to provide a non-reciprocal circuit device for microwaves, which is more reliable.

[0015]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and comprises laminating an unfired magnetic material layer with an electrode material interposed therebetween. By using a magnetic material for microwaves formed by integrally firing, the complicated manual work can be omitted and the number of parts can be reduced.

That is, the non-reciprocal circuit device for microwave according to the present invention is arranged such that the magnetic material for microwaves and the magnetic material for microwaves are electrically insulated from each other across the magnetic material layer. A plurality of center electrodes formed in planes at different height positions and arranged so as to cross each other, and at least one pair of capacitor take-out insides arranged with the magnetic layer separated in the microwave magnetic body An electrode, and a plurality of external electrodes formed on the outer surface of the magnetic body and electrically connected to the center electrode and the capacitance extracting electrode, respectively, wherein an impedance matching capacitance is provided between the capacitance extracting electrodes. This is a microwave non-reciprocal circuit device to be taken out.

[0017]

In the microwave non-reciprocal circuit device according to the present invention, a plurality of center electrodes and a capacitance extracting internal electrode for forming an impedance matching capacitor are arranged in the microwave magnetic body as described above. Since such a microwave magnetic body is formed by using a ceramic lamination / integral firing technique, a complicated manual assembling process of a portion including the center electrode can be omitted. In addition, since both the electrical insulation and the matching capacitance between the plurality of center electrodes are achieved or configured using the magnetic layer, the number of components can be significantly reduced.

Further, since the plurality of center electrodes are formed in the magnetic material for microwaves by using the ceramic lamination / integral firing technique, relative displacement between the center electrodes hardly occurs and the miniaturization is promoted. Even in this case, a highly reliable microwave non-reciprocal circuit device can be provided.

Further, since the dielectric loss of the microwave magnetic material is relatively small, the impedance matching capacitance is formed by using the above-mentioned microwave magnetic material, so that a matching circuit capacitor having a high Q value is formed. be able to.

Therefore, according to the present invention, it is possible to provide a small, inexpensive and highly reliable microwave non-reciprocal circuit device.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing embodiments of the non-reciprocal circuit device for microwave of the present invention. In the following, the structure of the non-reciprocal circuit device for microwave will be clarified by first describing the method of manufacturing the non-reciprocal circuit device for microwave of the embodiment.

A magnetic mixed powder containing yttrium oxide (Y ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ) in a weight ratio of 46:54 is calcined at a temperature of 800 to 1200 ° C. A powder was made.

The calcined powder obtained as described above is pulverized,
It was dispersed in an organic solvent together with a polyvinyl alcohol-based binder to prepare a magnetic slurry. Using the obtained magnetic slurry, several tens μm in thickness was obtained by a doctor blade method.
A magnetic green sheet having a uniform thickness of m was formed, and the magnetic green sheet was punched out so that the planar shape was a rectangle of 40 mm × 20 mm.

A plurality of punched magnetic green sheets are prepared, and as shown in FIG. 1, a conductive paste is printed on one main surface of some of the green sheets to form a center electrode and an internal electrode for extracting capacitance. did.

That is, in FIG. 1, a plurality of magnetic green sheets 1 to 8 are prepared. On the upper surface of the magnetic green sheet 2, one edge 2a to the other edge 2b
The center electrode 9 is formed so as to reach. By printing a conductive paste on the upper surfaces of the magnetic green sheets 3 and 4, respectively, the space between the side edges 3a and 3b and the side surface 4 is formed.
The center electrodes 10 and 11 are printed so as to reach between a and 4b.

The above-mentioned center electrodes 9 to 11 are formed so as to be rotated by 120 degrees around the center of the upper surface of the magnetic green sheet 2 in a state where the magnetic green sheets 2 to 4 are stacked. ing.

On the upper surface of the magnetic green sheet 5, an internal electrode 1 for forming a capacitance for an impedance matching circuit is provided.
On the upper surface of the magnetic green sheet 6, there are formed internal electrodes 16 to 18 which also constitute impedance matching circuit capacitors. Internal electrode 13 and internal electrode 16, internal electrode 14 and internal electrode 17, internal electrode 15
The internal electrodes 18 are formed so as to overlap in the thickness direction via the magnetic green sheet 5 after being laminated. Further, the internal electrodes 13 to 18 are extended to the side edges 5a, 5b and the edge 5c of the magnetic green sheet 5 and the side edges 6a, 6b and the edge 6c of the magnetic green sheet 6, respectively.

A ground electrode 19 is formed on the entire upper surface of the magnetic green sheet 7. Further, the above-mentioned electrodes are not formed on the magnetic green sheets 1 and 8 arranged above and below.

Next, the magnetic green sheets 1 to 8 shown in FIG. 1 were laminated in the direction shown in the figure and pressed in the thickness direction to obtain a laminate. By firing the thus obtained laminate at a temperature of 1300 to 1500 ° C., a sintered body shown in FIG. 2, that is, a magnetic body for microwaves 20 was obtained. In the microwave magnetic body 20, different heights are set so that a plurality of center electrodes 9 to 11 cross each other as seen through the inside, but are electrically insulated through the magnetic layer. Formed at the location. In addition, the center electrode 9 to
Below the portion where 11 is formed, the internal electrodes 13 to 15 and the internal electrodes 16 to 18 are formed at different height positions. Internal electrodes 16-18
The above-described ground electrode 19 is formed on the entire surface below the position where is formed.

Next, external electrodes 20a to 20f were formed on the outer surface of the microwave magnetic body 20. External electrode 2
0a to 20f, a conductive paste containing a metal powder such as Cu, Ag-Pd, and Ag and a glass frit is applied, and 90a to 20f are applied.
It can be formed by baking at a temperature of about 0 to 1200 ° C. However, the external electrodes 20a to 20f
May be formed by another conductive film forming method such as plating or sputtering. Further, the material for forming the external electrode is not limited to the above-described material, and a material containing another conductive material can be used as appropriate.

As described above, the non-reciprocal circuit device for microwave of this embodiment can be obtained. In this non-reciprocal microwave device, one end of the center electrode 9 is commonly connected to the internal electrodes 15, 18 and the ground electrode 19 and the external electrode 20a, and the other end of the center electrode 9 is connected to the external electrode 2a.
0d is electrically connected to the ground electrode 19.
One end of the center electrode 10 is electrically connected to the ground electrode 19 by the external electrode 20b. The other end of the center electrode 10 is electrically connected to the internal electrodes 13, 16 and the ground electrode 19 by an external electrode 20e. Further, one end of the center electrode 11 is connected to the internal electrodes 14 and 17 and the ground electrode 1.
9 is connected in common with an external electrode 20c, and the other end of the center electrode 11 is connected to an earth electrode 19 by an external electrode 20f.
Is electrically connected to Therefore, the upper and lower sides of the microwave non-reciprocal circuit element, that is, the microwave magnetic body 2
Forming a magnetically closed magnetic circuit by placing permanent magnets above and below zero and sandwiching the permanent magnets with a metal yoke so that a DC magnetic field is applied to the portion where the center electrodes 9 to 11 intersect. Thus, a non-reciprocal circuit device that can be used as a circulator or an isolator can be configured.

As described above, in the microwave non-reciprocal circuit device of this embodiment, electrical insulation between the plurality of center electrodes 9 to 11 is achieved by the magnetic layer of the microwave magnetic body 20. And the internal electrodes 13 to 15 and the internal electrode 16
To 18 are also constituted by the magnetic layer of the microwave magnetic body 20. Therefore, the number of components required to constitute the main part of the microwave non-reciprocal circuit device can be significantly reduced as compared with the conventional microwave non-reciprocal circuit device.

In addition, since the microwave magnetic body 20 is formed by using the ceramic lamination / integral firing technique as described above, the assembling process can be simplified, and a complicated manual assembling process is omitted. can do. Therefore, a low-cost and highly reliable microwave irreversible circuit device can be provided, and the miniaturization of the microwave irreversible circuit device can be coped with.

In the above embodiment, the microwave magnetic body 20 is obtained by sintering a laminate of magnetic green sheets with an internal electrode and a center electrode interposed therebetween. The magnetic substance-containing paste is printed on a base material made of a synthetic resin film or the like, and after drying, the conductive paste is printed and dried.By repeating a series of steps, the laminate formed on the base material is sintered. You may get it.

Further, for the production of the magnetic green sheet, it is not always necessary to use the doctor blade method as described above, but another molding method such as extrusion molding may be used.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view for explaining a magnetic green sheet used to obtain a microwave non-reciprocal circuit device according to one embodiment of the present invention and the shape of an electrode formed thereon.

FIG. 2 is a schematic perspective view for explaining a microwave non-reciprocal circuit device according to an embodiment.

FIG. 3 is a perspective view for explaining a step of assembling a conventional microwave non-reciprocal circuit device.

FIG. 4 is an exploded perspective view for explaining a step of assembling a conventional microwave non-reciprocal circuit device.

FIG. 5 is a cross-sectional view showing a main part of a conventional microwave non-reciprocal circuit device.

[Explanation of symbols]

9-11: Central electrode 13-18: Internal electrode for constituting impedance matching capacitor 20: Microwave magnetic body 20a-20f: External electrode

Continuation of the front page (72) Inventor Kunisaburo Banno 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-63-232421 (JP, A) JP-A-5-205 304404 (JP, A) JP-A-5-22003 (JP, A) JP-A-3-86608 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01P 1/383 H01P 1 / 36

Claims (1)

(57) [Claims] 1. An irreversible circuit for micros using a magnetic material for microwaves obtained by laminating unfired magnetic material layers with an electrode material interposed therebetween and firing the obtained magnetic raw chips. An element, wherein the microwave magnetic body and, in the microwave magnetic body, are formed in planes at different height positions so as to be electrically insulated from each other across a magnetic layer. And a plurality of central electrodes arranged so as to cross each other, at least one pair of capacitance extracting internal electrodes arranged with a magnetic layer in the microwave magnetic body, and an outer surface of the magnetic body A plurality of external electrodes, each of which is formed and electrically connected to the center electrode and the capacitance extracting internal electrode, respectively, and a impedance matching capacitance is extracted between the capacitance extracting electrodes. Non-reciprocal circuit element for black wave.