JPH08330811A - Concentrated constant-type circulator - Google Patents

Abstract

PURPOSE: To provide a small circulator of a wide band by setting a laminated assembly to be a hexagon, arranging input/output electrodes at every other side, arranging a ground electrode on a different side and shorting the length of one side where the input/output electrode is arranged. CONSTITUTION: The concentrated constant-type circulator is composed of the layer of an upper ground electrode, an upper input/output electrode, the upper part of the mesh center conductor of two parallel lines, the lower part of the mesh center conductor part of the two parallel lines, a lower ground electrode and a lower input/output electrode. A thin board constituting the upper ground electrode and the upper input/output electrode is constituted by printing an electrode 3a becoming the ground electrode and electrodes 8aa, 8ba and 8ca becoming the input/output electrodes on a ferri magnetic body 2a. The side of a part where the input/output electrodes 8aa, 8ba and 8ca are arranged is made shorter than the wide where the ground electrode 3a is arranged. Thus, the circulator can be miniaturized and the band can be made wide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumped-constant circulator, which is a microwave nonreciprocal element using a ferrimagnetic material, and has a smaller size and wider bandwidth.

[0002]

2. Description of the Related Art In recent years, semiconductor devices such as ICs and transistors, multilayer chip capacitors, multilayer chip inductors,
Along with the miniaturization of chip resistors and other electronic components, the miniaturization and thinning of microwave devices that are surface-mounted with these are rapidly progressing. In such a movement, miniaturization of a lumped constant type circulator, which is a microwave non-reciprocal element that is extremely important in constructing a microwave device, has been delayed. Recently, a paste containing metal fine particles is printed on a thin plate formed by mixing fine particles of ferrimagnetic material and a binder, a plurality of thin plates printed with the paste are laminated, and the laminate is baked at a high temperature. A laminated assembly in which external electrodes are printed and printed on the side surface of the integrally fired product has been attracting attention as an integrated technique for producing an ultra-small lumped constant circulator and the like. (Miura et al. “Characteristics of magnetic circuit optimized circulator” IEICE Technical Report MW94-14 (1994)
—05)) The present inventors have already proposed a laminated type lumped constant circulator. (Takeda et al .; “Concentrated constant type circulator” Japanese Patent Application No. 6-2864
32)))

[0003]

Next, the problems of the prior art lumped constant type circulator using the above-mentioned stacking technique will be described in detail based on specific examples. FIG. 11 is a regular hexagonal laminated thin plate 2′a of a ferrimagnetic material having no pattern printed thereon.
Indicates. The dotted line in the figure is a guide line corresponding to the mesh-shaped central conductor of two parallel lines. FIGS. 12 and 13 show the shapes of the respective elements on the ferrimagnetic material printed to form the mesh-shaped central conductor of the stacked lumped constant type three-terminal pair circulator as an example of the prior art. Similarly, the outer shape is a regular hexagon. The hatched portion shows a portion where the paste containing the metal fine particles is printed. Figure 12
It is one thin plate for forming a mesh-shaped center conductor. On the ferrimagnetic material 2'b, the portions 1'a, 1'b, 1'c to be the input and output terminals of the central conductor are paste-printed.
The ends of these lines are parallel 2 lines, and are bent outward in the vicinity of the center of the ferrimagnetic material, and through holes 51a, 51'a, 51b, 51'b, 51c, 51'c.
It is connected to the. FIG. 13 is another thin plate that constitutes a mesh-shaped central conductor of two parallel lines. The through holes 51a, 51'a, 51 are formed on the ferrimagnetic material 2'c.
Land 61 corresponding to b, 51'b, 51c, 51'c
a, 61'a, 61b, 61'b, 61c, 61'c are paste-printed. The ends of these lines become two parallel lines and are combined to form ground conductors 31'a and 31 '.
b, 31'c. The laminated lumped constant circulator of the prior art is composed of ferrimagnetic thin plates 2'a, 2 '.
A laminated assembly is produced by printing or applying a pattern as shown in FIG. 14 on the outside of the integrally fired product obtained by laminating and press-bonding b and 2′c. In the figure, 8'a, 8'b,
8'c is an input / output electrode, and 3 is a ground electrode. Figure 15 shows
FIG. 15 is a sectional view of the completed stacked lumped constant circulator taken along the line AA ′ in FIG. 14. Input / output electrodes 8'a, 8'b,
8'c, the ground electrode 3 is painted not only on the upper and lower surfaces but also on the side surfaces. Actually, in order to operate as a lumped constant type circulator, a magnetic field H is applied perpendicularly to the main surface of the stacked assembly as shown in FIG.
It is necessary to connect the load capacitance CL to b and 8'c.

Next, the problem when the lumped constant type circulator is miniaturized by using the laminating technique will be described with reference to the equivalent circuit of FIG. In the figure, 11 is an ideal circulator, and a parallel resonance circuit having a load capacitance CL and an equivalent inductance L is connected in parallel to each terminal 21, 22, 23. A line capacitance Cw is connected between the terminals. At this time, the operating frequency f of the lumped constant circulator is given by the following equation.

[0005]

[Equation 1]

Therefore, when the lumped-constant circulator is miniaturized by using the above-mentioned stacking technique, the equivalent inductance L becomes small. Therefore, when the lumped-constant circulator is operated at the same frequency, CL
And Cw must be increased. This requires increasing the capacity of the external capacitor, which is not preferable for downsizing. The specific bandwidth w at this time is given by the following equation. (Konishi; "Recent Microwave Technologies Using Ferrites" The Institute of Electronics and Communication Engineers (1965))

[0007]

[Equation 2]

Where | S "| is the reverse voltage loss, kf
Is an irreversible filling factor, and η is a constant indicating the operating state of the circulator determined by the external magnetic field H. ｜ S "｜ and η
Is constant, the specific bandwidth w is proportional to kf. kf
Represents the ratio of the energy contributed by the ferrimagnetic material to the total magnetic energy. The miniaturization of the lumped-constant circulator by making full use of the lamination technique is not only to reduce L, but also to reduce this kf at the same time. From this point of view, when looking at FIG. 16 of the prior art, not all of the ferrite laminated assemblies contribute to the circulator operation. In particular, the input / output electrode section does not contribute to this. For this reason, it is difficult to obtain a wide bandwidth with the conventional ultra-small integrated lumped constant circulator. By the way, in the conventional structure shown in FIG. 16, the specific bandwidth measured with 20 dB reverse loss is about 4%.

The present invention has been made in view of the above-mentioned problems of the prior art and the problems of miniaturization due to the recent manufacturing technology, and a lumped constant circulator which is a microwave non-reciprocal element. Concerning miniaturization and wide band. That is, an object of the present invention is to reduce the equivalent inductance L as much as possible and reduce the equivalent inductance L as much as possible when miniaturizing by using the above-mentioned integration technique of laminating thin plates, and to maintain a wide band, the irreversible filling factor kf. It is to provide a method of suppressing deterioration of the.

[0010]

A lumped constant type circulator of the present invention is a thin plate formed by mixing fine particles of a ferrimagnetic material and a binder, and a printing thin plate in which a paste containing metal fine particles is printed on the main surface of the thin plate. A laminated body in which a plurality of thin plates including the printed thin plate are laminated, an integrally fired product in which the laminated body is fired at high temperature to be integrated, a laminated assembly in which external electrodes are printed and baked around the integrally fired product, and the laminated body In a lumped constant type circulator in which a DC magnetic field is applied to an assembly, the assembly has a hexagonal shape, and input / output electrodes are arranged on every other side.
Also, the ground electrodes are arranged every other side on a side different from the input / output electrodes, and the length of one side of the hexagon where the input / output electrodes are arranged is one side of the hexagon where the ground electrodes are arranged. It is characterized by being shorter.

[0011]

According to the above construction, the portion that acts on the non-reciprocal effect can be made large, and as a result, it is possible to construct a lumped constant type circulator which is a microwave non-reciprocal element having a reduced size and a wider band.

[0012]

The main object of the present invention is to provide an equivalent inductance L.
In order to suppress the decrease of the length, the shape of the regular hexagon is changed so that the side length of the input / output electrode portion is shorter than the side length of the ground electrode portion. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the green sheets 2a and 2
FIG. 6 is an overall schematic view of the respective elements of FIGS. 2, 3, 4, and 5 printed on b and 2c. The same shape is printed repeatedly. After stacking and press-bonding these four types of green sheets, they are cut with a dicing saw or the like, and each element is taken out in pieces. The cut elements are fired at a high temperature of 1000 ° C. or higher to be integrated. External electrodes (input / output electrodes, ground electrodes) are baked on this integrally fired product to complete a laminated assembly of a laminated lumped constant circulator. 2, FIG. 3, FIG. 4, and FIG. 5 show the shape of each element on the ferrimagnetic material printed to form the stacked lumped constant type three-terminal pair circulator as an embodiment of the present invention. Each has a hexagonal shape, but it is not a regular hexagon. The hatched portion shows a portion where the paste containing the metal fine particles is printed. In this example, a paste containing platinum was used. Of course, palladium paste can also be used. FIG. 2 is a thin plate that constitutes the upper ground electrode and the upper input / output electrode. On top of the ferrimagnetic material 2a,
Electrode 3a to be a ground electrode, electrode 8a to be an input / output electrode
a, 8ba, and 8ca are printed. In this case, the total thickness of the green sheets was 200 μm.
In this example, since a working process with a thickness of 100 μm as a standard was used, one unprinted dummy green sheet was inserted between them. FIG. 3 is one thin plate for forming the upper part of the mesh-shaped central conductor of the parallel two lines. On the ferrimagnetic body 2b, the input / output conductor portion 1a of the central conductor,
1b and 1c are paste-printed. The ends of these lines are parallel two lines, near the center of the ferrimagnetic material,
Bent outwards, through holes 5a, 5 '
a, 5b, 5'b, 5c, 5'c. In this case, the green sheet used was an extremely thin one having a thickness of 50 μm. FIG. 4 is another thin plate which constitutes the lower part of the mesh-shaped central conductor of the parallel two lines. The through holes 5a, 5'a, 5b, 5'b, 5 are formed on the ferrimagnetic material 2c.
Lands 6a, 6'a, 6b, 6'corresponding to c, 5'c
b, 6c, 6'c are provided, and the ends of these lines are parallel 2 lines, respectively, and are combined to form the ground conductor portion 31.
It is connected to a, 31b, and 31c. In this case, the total thickness of the green sheets was 200 μm. Through holes 5a, 5'a, 5b, 5'b, 5 in FIG.
c, 5'c, and the land and through holes 6a, 6'of FIG.
a, 6b, 6'b, 6c, 6'c are ferrimagnetic materials 2b,
It is designed to be accurately aligned by stacking 2c. By stacking the two, a mesh-shaped center conductor consisting of three sets of parallel two lines is completed. FIG. 5 is a thin plate constituting the lower ground electrode and the lower input / output electrode. The conductor 3b serving as a ground electrode and the conductors 8ab, 8bb, 8cb serving as input / output electrodes are printed on the ferrimagnetic material 2d. The thickness of the green sheet in this case is 100 μm as a whole.
I used the one. FIG. 6 shows that each of FIG. 2, FIG. 3, FIG. 4 and FIG.
FIG. 10 is a schematic cross-sectional view of a finished product in which 10a is baked.
The plan view from the top surface when these are stacked is shown in FIG.
Is the same as The cross-sectional view of FIG. 6 shows the case as seen from AA ′ in FIG. Although not shown in the figure, the side surface external electrode 9
Of course, b, 9c, 10b and 10c are also provided. The side surface external electrodes 9a, 9b, 9c are respectively connected to the input / output conductor portions 1a, 1b, 1c of the mesh center conductor. Side electrode 1
0a, 10b and 10c are connected to the ground conductor portions 31a, 31b and 31c of the mesh-shaped center conductor, respectively, and also tightly connected to the upper and lower ground electrodes 3a and 3b. Figure 7
FIG. 7 is a perspective view of FIG. 6 which is a completed laminated assembly. The side surface external electrodes 9c and 10b are visible. In the figure, the arrow indicates the DC magnetic field H and determines the impedance of the lumped constant circulator. On the other hand, CL is an external load capacity, to which a chip capacitor or the like is connected. This, together with the line capacitance Cw, determines the operating frequency of the lumped constant circulator.

Now, the features of the present invention will be described by comparing FIG. 16 of the prior art with FIG. 7 of the embodiment of the present invention. The structure of the prior art is a regular hexagon, and the input / output terminal electrode portion is inside the regular hexagon. Therefore, the ground conductor electrode portion becomes narrow, and the portion that contributes to the non-reciprocal effect is small. That is,
In the equation (2), kf is small and a sufficient specific bandwidth cannot be secured. In contrast, in the structure of the present invention shown in FIG. 7, the input / output terminals are projected forward, so that the non-reciprocal portion is not damaged. FIG. 8 is a sectional view showing a case where a laminated assembly of the present invention is actually mounted in a magnetic circuit to realize a microminiature lumped constant type circulator. In the figure, 4a and 4b are upper and lower yokes. 7
Is a permanent magnet. Reference numeral 12 is a dielectric substrate for taking out the input / output electrodes to the outside. With such a structure, a specific bandwidth of 7% could be realized. Therefore, by using the method of the present invention, it is possible to minimize the deterioration of the characteristics even when the size is reduced by the stacking technique. FIG. 9 shows another embodiment of the present invention. When the frequency to be applied is high, the line capacitance Cw of the three sets of mesh-shaped center conductors can be sufficient as the load capacitance CL. In this case, since an externally attached capacitor is unnecessary, the input / output electrodes can be directly taken out as the input / output terminals 21, 22, 23 as shown in the figure. In this embodiment, the dimensions of the permanent magnet 7, the upper yoke 4'a, and the lower yoke 4'b are smaller than those of the ferrimagnetic laminated assembly. FIG. 10 is a sectional view of FIG. In this example, a dummy green sheet having no print pattern similar to that in FIG. 11 was used instead of FIG. Moreover, the green sheet of FIG. 5 is not used. The external electrodes (input / output electrodes, ground electrodes) are realized by printing / applying a metal paste on the integrally fired product in the same manner as described in FIG. 15 of the related art. As a result, it can be thinned by the thin plate in FIG.

[0014]

As described above in detail with reference to the embodiments, in the laminated assembly of the ferrimagnetic material, the side of the portion where the input / output electrodes are arranged is smaller than the side where the ground conductor is arranged. The stacked lumped constant circulator of the present invention using the characteristic hexagonal shape is easy to manufacture, and at the same time, it is possible to reduce the size and increase the bandwidth. It can be seen that a constant type circulator can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view of the present invention in which a plurality of element patterns are printed on one ferrimagnetic thin plate.

FIG. 2 is an element pattern diagram according to the present invention printed on a thin ferrimagnetic material plate.

FIG. 3 is an element pattern diagram according to the present invention printed on a thin ferrimagnetic material plate.

FIG. 4 is an element pattern diagram according to the present invention printed on a thin ferrimagnetic material plate.

FIG. 5 is an element pattern diagram according to the present invention, which is printed on a ferrimagnetic thin plate.

FIG. 6 is a schematic structural sectional view showing an embodiment of the present invention.

FIG. 7 is a schematic perspective view showing an embodiment of the present invention.

FIG. 8 is a schematic structural sectional view showing an embodiment of the present invention.

FIG. 9 is a schematic perspective view showing an embodiment of the present invention.

FIG. 10 is a schematic sectional view showing an example of the present invention.

FIG. 11 is an element diagram in which a conventional pattern is not printed.

FIG. 12 is an element pattern diagram printed on a conventional ferrimagnetic thin plate.

FIG. 13 is an element pattern diagram printed on a conventional ferrimagnetic thin plate.

FIG. 14 is a top view pattern diagram printed and applied to a conventional ferrimagnetic laminated assembly.

FIG. 15 is a schematic structural sectional view showing an embodiment of the prior art.

FIG. 16 is a schematic perspective view showing an example of prior art.

FIG. 17 is an equivalent circuit diagram of a lumped constant circulator.

[Explanation of symbols]

1, upper center conductor, 2 ferrimagnetic material, 3 ground conductor, 4
Yoke, 5 through holes, 6 lands, 7 permanent magnets, 8 input / output conductors, 9 input / output external electrodes, 10 grounded external electrodes, 11 ideal circulators, 12 dielectric bases.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Manabu Yumoto 33-12 Minamieicho, Tottori-shi, Tottori Prefecture Hitachi Ferrite Co., Ltd.

Claims (2)

[Claims] 1. A thin plate formed by mixing fine particles of a ferrimagnetic material and a binder, a printed thin plate on which a paste containing metal fine particles is printed on the main surface of the thin plate, and a laminate in which a plurality of thin plates including the printed thin plate are laminated. Body, an integrally fired product obtained by firing the laminated body at a high temperature to integrate it, a laminated assembly in which external electrodes are printed and printed around the integrally fired product, and a lumped constant type in which a DC magnetic field is applied to the laminated assembly. In the circulator, the assembly has a hexagonal shape, and the input / output electrodes are arranged every other side,
Also, the ground electrodes are arranged every other side on a side different from the input / output electrodes, and one side of the hexagon on which the input / output electrodes are arranged is longer than one side of the hexagon on which the ground electrodes are arranged. A lumped constant type circulator characterized by being short. 2. The lumped constant type circulator according to claim 1, wherein the input / output electrodes directly serve as input / output terminals for connection with an external circuit.