JP4288638B2 - Lumped constant type nonreciprocal circuit device - Google Patents

Description

【０００９】
この様にして得たＳｒフェライト磁石２ｂとＮｄ−Ｆｅ−Ｂ系磁石２ａとを耐熱性接着剤を用いて貼合わせて一体の永久磁石とした。この永久磁石をフェリ磁性体に直流磁界を印加するように、上下ヨーク１、１２間に配置し本発明の非可逆回路素子を構成した。この様に構成すれば、Ｓｒフェライト磁石単体で得ていた磁力を、従来よりも総厚を薄くし構成た場合であっても容易に得ることが出来、また残留磁束密度Ｂｒの温度特性も希土類磁石のみで構成する場合よりも大きく出来、この結果、温度特性を実用上問題のない程度に維持しつつ小型化した非可逆回路素子を得ることが出来た。
【００１０】
【発明の効果】
以上説明したように、本発明によれば温度特性を実用上問題のない程度に維持しつつ小型化した非可逆回路素子を得ることが出来る。
【図面の簡単な説明】
【図１】本発明の一実施例に係る非可逆回路素子の分解斜視図である。
【図２】従来の非可逆回路素子の分解斜視図である。
【符号の説明】
１ 上ケース
２、２ａ、２ｂ 永久磁石
３ フェリ磁性体
１２ 下ヨーク[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an irreversible circuit element having irreversible transmission characteristics with respect to a high-frequency signal. Specifically, the irreversible circuit is used in a mobile communication system such as a mobile phone and is generally called an isolator or a circulator. It relates to an element.
[0002]
[Prior art]
Conventionally, there are non-reciprocal circuit elements such as isolators and circulators as one of transmission / reception circuit components such as mobile phones and automobile phones used in the microwave band and UHF band. In general, an isolator or a circulator is used for the purpose of preventing the amplifier from being damaged, and has a function of reducing the insertion loss in the signal transmission direction and increasing the reverse loss in the reverse direction. Hereinafter, the present specification will be described taking an isolator as an example of the non-reciprocal circuit device.
[0003]
FIG. 2 is an exploded perspective view showing an example of an isolator. This isolator includes an upper case 1, a magnet 2, an assembly 20, plate capacitors 8, 9, 10, a dummy resistor 11, a resin case 7, and a lower case 12. The assembly 20 prepares a conductive plate having a structure in which three central conductors 4, 5 and 6 project radially from a disk-shaped shield plate, and a ferrite disk (ferrimagnetic material) is formed on the disk-shaped portion of the conductive plate. ) 3 is arranged. Then, the three central conductors 4, 5, 6 are folded and overlapped. At this time, each of the central conductors 4, 5, 6 is insulated and overlapped.
[0004]
The resin case 7 has a circular recess 13a for an assembly at the center, and recesses 13b, 13c, and 13d for capacitive elements around the resin case 7. Connection electrodes are formed on the bottom of the concave portion for the capacitive element and the concave portion 13a for the assembly. The connection electrode is composed of an integral conductor plate of about 0.1 mm, exposed on the bottom surface side, and constitutes an external terminal on the side surface. Capacitance elements 8, 9, and 10 are inserted into the capacitor element recesses of the resin case 7, respectively. This capacitive element is a plate capacitor having electrodes formed on the upper and lower surfaces thereof, and is solder-connected to the electrode on the lower surface and the connection electrode formed on the bottom of the recess. Further, the resistance element 11 is disposed, and one electrode of the resistance element 11 is solder-connected to the connection electrode.
Next, the assembly 20 described above is disposed in the circular recess 13 a for the assembly of the resin case 7. One end of the center conductor 5 is connected to the electrode on the upper surface of the capacitive element 9 and one terminal electrode of the resistance element 11. One end of the center conductor 4 is connected to the electrode on the upper surface of the capacitive element 8. One end of the center conductor 6 is connected to an electrode on the upper surface of the capacitive element 10. Then, the resin case 7 is disposed on the lower case 12. And the permanent magnet 2 which applies a direct-current magnetic field to the magnetic body 3 is positioned in the upper case 1, and the upper case 1 and the lower case 12 are fitted, and the isolator is comprised.
[0005]
[Problems to be solved by the invention]
In recent years, along with the miniaturization of passive components such as semiconductor elements such as ICs and transistors, multilayer chip capacitors, multilayer chip inductors, chip resistors, etc., the miniaturization and thinning of microwave devices that have been surface-mounted have rapidly progressed. Yes. In such a movement, a lumped constant type circulator / isolator, which is a nonreciprocal circuit element that is extremely important in configuring a microwave device, is also required to be reduced in size and thickness.
As a method for reducing the size of these nonreciprocal circuit elements such as isolators and circulators, it is conceivable to use a high-performance magnet to reduce the size of the magnet while maintaining the necessary magnetic force. Conventionally, since the temperature characteristic of saturation magnetization of garnet ferrite used as the ferrimagnetic material 3 is as large as −0.4 to −0.2% / ° C., an Sr ferrite magnet having a large residual magnetic flux density Br temperature characteristic is used as the permanent magnet. In general, the non-reciprocal circuit element is configured to have a small temperature coefficient. However, the magnetic properties of the Sr ferrite magnet are as follows: the residual magnetic flux density Br is about 0.45 T, and (BH) max. Is about 40 KJ / m ³ , so there is a natural limit to downsizing.
As the magnet having a stronger magnetic force than the Sr ferrite magnet, RCo ₅ type, R ₂ Co ₁₇ type, R—Fe—B type, R—Fe—N type (R is one of rare earth elements including Y or There are two or more types of magnets, etc., but since these magnets have flatter temperature characteristics than Sr ferrite magnets, the temperature characteristics of the ferrimagnetic material cannot be eliminated, and the temperature of the isolator and the circulator element as a whole. It was difficult to satisfy the characteristics.
Accordingly, the present invention is to provide a non-reciprocal circuit device that is miniaturized while maintaining temperature characteristics to such an extent that there is no practical problem.
[0006]
[Means for Solving the Problems]
The present invention is a non-reciprocal circuit device comprising a ferrimagnetic body in which a plurality of central conductors are arranged, and a permanent magnet that applies a DC magnetic field that is arranged on the central conductor side of the ferrimagnetic bodies,
A laminate of the two or more plate-like permanent magnets having different temperature coefficient as a permanent magnet, at least one is Sr ferrite magnets of the permanent magnet, and the other one is a rare earth magnet, Sr ferrite of the permanent magnet This is a lumped-constant nonreciprocal circuit device in which a magnet is opposed to a central conductor provided on a ferrimagnetic body and a rare earth magnet is used as an upper case side .
At least one of the two or more kinds of permanent magnets is RCo ₅ series, R ₂ Co ₁₇ series, R—Fe—B series, R—Fe—N series (R is one or two of rare earth elements including Y) Any one of the rare earth magnets described above is preferable.
It is also preferable that a plate-like Sr ferrite magnet and a rare earth magnet are bonded together with a heat resistant adhesive to form an integral permanent magnet.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
A nonreciprocal circuit device according to an embodiment of the present invention will be described with reference to an exploded perspective view of FIG. This nonreciprocal circuit element has many parts similar to those of the conventional nonreciprocal circuit element, and different parts will be described below. In the nonreciprocal circuit device of the present invention, a permanent magnet that applies a DC magnetic field to a ferrimagnetic material is configured using two or more types of permanent magnets 2a and 2b having different temperature coefficients. Here, the two or more kinds of permanent magnets having different temperature coefficients may be appropriately selected from Sr ferrite magnets and rare earth magnets shown in Table 1. The shape of the permanent magnet is preferably a plate from the viewpoint of ease of processing. For example, if it is a Nd-Fe-B magnet, dry powder or dry powder as a raw material powder and a mixture of organic solvent, mineral oil or synthetic oil Can be obtained by powdering into a mold cavity, molding into a plate shape in a magnetic field, drying the resulting molded body as necessary, sintering, and heat treatment. The Sr ferrite magnet can be obtained by preparing a dry powder or a mixture of dry powder and water as a raw material powder, forming it into a plate shape in a magnetic field, and drying and sintering the resulting molded body as necessary. I can do it.
[0008]
[Table 1]

[0009]
The Sr ferrite magnet 2b and the Nd—Fe—B magnet 2a thus obtained were bonded together using a heat resistant adhesive to form an integral permanent magnet. The permanent magnet is disposed between the upper and lower yokes 1 and 12 so as to apply a DC magnetic field to the ferrimagnetic material, thereby constituting the nonreciprocal circuit device of the present invention. With this configuration, the magnetic force obtained with a single Sr ferrite magnet can be easily obtained even when the total thickness is made thinner than before, and the temperature characteristics of the residual magnetic flux density Br are also rare earths. As a result, it was possible to obtain a non-reciprocal circuit device that was reduced in size while maintaining the temperature characteristics to such an extent that there was no practical problem.
[0010]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a nonreciprocal circuit device that is miniaturized while maintaining temperature characteristics at a level that does not cause any practical problems.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a non-reciprocal circuit device according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a conventional non-reciprocal circuit device.
[Explanation of symbols]
1 Upper case 2, 2a, 2b Permanent magnet 3 Ferrimagnetic material 12 Lower yoke

Claims (3)

A non-reciprocal circuit device comprising a ferrimagnetic body in which a plurality of central conductors are arranged, and a permanent magnet that applies a DC magnetic field that is arranged on the central conductor side of the ferrimagnetic bodies,
A laminate of the two or more plate-like permanent magnets having different temperature coefficient as a permanent magnet, at least one is Sr ferrite magnets of the permanent magnet, and the other one is a rare earth magnet, Sr ferrite of the permanent magnet the magnet is the center conductor and a counter provided in the ferrimagnetic body, a lumped constant type non-reciprocal circuit element, characterized in that the upper case side a rare earth magnet. At least one of the two or more kinds of permanent magnets is RCo ₅ series, R ₂ Co ₁₇ series, R—Fe—B series, R—Fe—N series (R is one or two of rare earth elements including Y) 2. The lumped constant type nonreciprocal circuit according to claim 1, wherein the lumped constant type nonreciprocal circuit is any one of the above rare earth magnets.   The lumped-constant nonreciprocal circuit according to claim 1 or 2, wherein a plate-like Sr ferrite magnet and a rare earth magnet are bonded together with a heat-resistant adhesive to form an integral permanent magnet.

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