JP4650962B2 - Lumped constant type nonreciprocal circuit device - Google Patents

Description

【００２５】
このように、本発明に使用する永久磁石は、従来よりも高い磁気特性を有している。
【００２６】
この実施例によると、５ｍｍ×５ｍｍ×高さ２ｍｍといった非常に小型、薄型の集中定数型非可逆回路素子を得ることが出来た。また、実施例の挿入損失特性を図２に、アイソレーション特性を図３に示す。本実施例によれば、２．４ＧＨｚ帯の集中定数型非可逆回路素子を５ｍｍ×５ｍｍ×高さ２ｍｍといった非常に小型に構成することができた。
また、本発明は、２ＧＨｚ以下の周波数であっても効果を発揮し、特に本発明によれば、高さ２ｍｍ以下の薄型の集中定数型非可逆回路素子を図ることに有効な技術である。
【００２７】
上記実施例は、アイソレータで説明したが、サーキュレータを同様の技術で構成できることは言うまでもない。また、本発明の永久磁石は、上記した基本組成を満足していれば、上記実施例の如く所望の特性の集中定数型非可逆回路素子を得ることができる。もちろん、永久磁石は円板形であっても良い。
【００２８】
【発明の効果】
本発明によれば、集中定数型非可逆回路素子の小型、薄型化を可能とするものであり、又２ＧＨｚ以上の高周波に対応した集中定数型非可逆回路素子を得ることができるものである。
【図面の簡単な説明】
【図１】本発明に係る一実施例の分解斜視図である。
【図２】本発明に係る実施例の挿入損失特性である。
【図３】本発明に係る実施例のアイソレーション特性である。
【図４】従来例の分解斜視図である。
【符号の説明】
１ 上ケース
２ 永久磁石
３ フェライト円板
４、５、６ 中心導体
７ 樹脂ケース
８、９、１０ 容量素子
１１ 抵抗素子
１２ 下ケース
１３ａ 中心導体部分用凹部
１３ｂ、１３ｃ、１３ｄ 容量素子用凹部
１４ａ アース電極
１５ａ、１５ｂ、１５ｃ 外部端子
１６ａ、１６ｂ、１６ｃ 端子電極部
１７ 抵抗素子用貫通凹部
１８ 凹部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lumped constant non-reciprocal circuit device such as an isolator or a circulator used in a microwave communication device.
[0002]
[Prior art]
In general, nonreciprocal circuit elements such as isolators and circulators have a function that hardly attenuates in the signal transmission direction and increases in the reverse direction. For example, they are used in the microwave band and the UHF band. It is used in a transmission / reception circuit unit of mobile communication devices such as mobile phones and automobile phones.
[0003]
FIG. 4 shows an exploded perspective view of a conventional lumped constant isolator. In this conventional example, a ground plate 30 is disposed on a lower case 21, and a ceramic substrate 40 is disposed thereon. The ceramic substrate 40 is formed with electrode patterns 43, 44, and 45 constituting a capacitive element, and has a through hole 41 in the center. One of the capacitive element electrode patterns 45 is connected to a dummy resistor 46, and the dummy resistor 46 is further connected to a ground electrode 47. The ground electrode 47 is connected to the ground plate 30 through a through hole 49. A central conductor portion is disposed in the through hole 41 of the ceramic substrate 40. The central conductor portion is composed of central conductors 56, 57, and 58 folded so as to enclose a ferrite disk (ferrimagnetic material) 50, and the central conductors are insulated from each other. The upper case 61 to which the permanent magnet 60 is bonded is fitted to the lower case 21 and configured. The center conductors 57 and 58 are drawn to the outside from the space 62 between the upper case 61 and the lower case 21 to constitute an input / output terminal.
[0004]
[Problems to be solved by the invention]
There is a strong demand for miniaturization and thinning of microwave communication devices such as cellular phones in which this lumped constant nonreciprocal circuit element is used, and there is a strong demand for a low cost, small and thin lumped constant nonreciprocal circuit element. Yes. Of course, it is necessary to satisfy the characteristics as a non-reciprocal circuit device. For this reason, various configurations, such as a surface mount type, a chip capacitor, and a flat plate capacitor, have been studied.
[0005]
In addition, a conventional permanent magnet is generally a ferrite magnet (SrO.nFe2O3) and has compatibility with garnet ferrite used as a ferrimagnetic material, and other magnets have not been studied much.
[0006]
In view of the above, an object of the present invention is to provide a lumped-constant nonreciprocal circuit device that can be reduced in size and thickness.
[0007]
[Means for Solving the Problems]
The present invention includes a plurality of central conductors, a ferrimagnetic body disposed in proximity to the central conductor, a capacitive component connected to the central conductor, and a permanent magnet that applies a DC magnetic field to the ferrimagnetic body. Is a lumped constant type non-reciprocal circuit element arranged in a metal case that also serves as a magnetic yoke, and (A _1-x R _x ) O · n [(Fe _1-y M _y ) _{2 is used} as the permanent magnet. O ₃ ] (atomic ratio) (A is Sr and / or Ba, R is at least one rare earth element including Y, and M is at least one selected from the group consisting of Co, Mn, Ni and Zn) 0.01 ≦ x ≦ 0.4, [x / (2.6n)] ≦ y ≦ [x / (1.6n)], 5 ≦ n ≦ 5.67 Featuring a ferrite magnet that has a substantially magnetoplumbite crystal structure Lumped constant type non-reciprocal circuit device.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
[0009]
In the present invention, it has been found that the use of a permanent magnet as described below as a permanent magnet for applying a DC magnetic field to a ferrimagnetic material enables reduction in size and thickness. _{(A 1-x R x)} O · n [(Fe 1-y M y) 2 O 3] ( atomic ratio) (A is Sr and / or Ba, R is at least one rare earth element including Y , M is at least one selected from the group consisting of Co, Mn, Ni and Zn), 0.01 ≦ x ≦ 0.4, [x / (2.6n)] ≦ y ≦ [x / (1. 6n)] is a ferrite magnet having a basic composition represented by 5 ≦ n ≦ 5.67 and substantially having a magnetoplumbite type crystal structure.
[0010]
In the permanent magnet, it is preferable that the R element and / or the M element are added in a pulverization step after calcination in a compound state. In addition, it is preferable that the R element and / or the M element are added in the mixing step before calcination in the state of a compound and also added in the pulverization step after calcination.
[0011]
In any case, it is preferable that the concentration of the R element is higher in the grain boundary than in the magnetoplumbite type crystal grains. When the R element is La and the M element is Co, or when the R element is La and the M element is Co, Mn and / or Zn, particularly excellent magnetic properties can be obtained.
[0012]
When the n value exceeds 6, a different phase other than the magnetoplumbite phase (for example, α-Fe ₂ O ₃ ) is generated, and the magnetic characteristics are greatly deteriorated. When the n value is less than 5, Br decreases greatly.
If the x value is less than 0.01, the effect of post-addition or pre- / post-addition is insufficient, and if it exceeds 0.4, the magnetic properties are conversely reduced.
The M element is preferably Co alone, or Co and Mn and / or Ni.
[0013]
According to the magnet of the present invention, compared with the conventional ferrite magnet, it has a high magnetic force and has good compatibility with the ferrimagnetic material, and the lumped constant type nonreciprocal circuit device can be reduced in size and thickness. Can do.
[0014]
Further, the frequency used in the conventional lumped constant nonreciprocal circuit element is in the vicinity of 1 MHz to 2 GHz. For a high frequency exceeding 2 GHz, a lumped constant nonreciprocal circuit element capable of obtaining satisfactory characteristics is formed. I couldn't. For this reason, distributed constant type nonreciprocal circuit elements are used at such high frequencies. According to the present invention, by using the above-described permanent magnet, a lumped constant nonreciprocal circuit device that can be used in a frequency band exceeding 2 GHz can be obtained, and the device can be made compact.
[0015]
An exploded perspective view of an embodiment according to the present invention is shown in FIG. In this embodiment, a conductive plate having a structure in which three central conductors 4, 5, and 6 project radially from a disk-shaped shield plate is prepared, and a ferrite disk 3 (ferrimagnetic) is formed on the disk-shaped portion of the conductive plate. Body). Then, the three central conductors 4, 5, 6 are folded and overlapped. At this time, the central conductors 4, 5, and 6 are insulated and overlapped. In this way, the central conductor portion is configured.
[0016]
Next, the resin case 7 has a circular concave portion 13a for the central conductor portion at the center, and has concave portions 13b, 13c, and 13d for the capacitive elements around it. A ground electrode 14a is formed at the bottom of the recesses 13a, 13b, 13c, and 13d. The ground electrode 14a is composed of an integral conductor plate, exposed on the bottom surface side, and constitutes ground external terminals (15a, 15b, etc.) among the external terminals on the side surface. Terminal electrode portions 16a, 16b, and 16c to which the central conductor is connected are formed. The terminal electrode portions 16a, 16b and 16c are electrically connected to external terminals (15c and the like) on the side surfaces. Further, a through recess 17 for arranging the resistance element is formed.
[0017]
Then, the resin case 7 is disposed on the lower case 12. At this time, the lower case 12 and the ground electrode 14a of the resin case 7 are electrically connected. The ground electrode 14a and the lower case 12 are opposed to each other with a wide installation area, and a sufficient ground can be obtained. The lower case 12 has a structure that matches the recess 18 at the bottom of the resin case 7. Thereby, surface mounting by the external terminal of the resin case 7 is enabled.
[0018]
Capacitance elements 8, 9, and 10 are inserted into the capacitor element recesses 13b, 13c, and 13d of the resin case 7, respectively. The capacitive element is a flat plate capacitor having electrodes formed on the upper and lower surfaces thereof, and the electrode on the lower surface and the ground electrode 14a formed on the bottom of the recess are connected by soldering. Further, the resistance element 11 is disposed in the through hole 17 for the resistance element, and one electrode of the resistance element 11 is disposed on the lower case 12 below the through recess 17 and is soldered.
[0019]
Next, the above-described center conductor portion is disposed in the circular recess 13 a for the center conductor portion at the center of the resin case 7. At this time, the disc-shaped shield plate of the central conductor portion is soldered to the ground electrode 14a. Thus, one end of the center conductor is grounded.
[0020]
One end of the center conductor 4 is connected to the electrode on the upper surface of the capacitive element 8 and one terminal electrode 25 of the resistance element 11. One end of the center conductor 5 is connected to the electrode on the upper surface of the capacitive element 9 and the terminal electrode portion 16b. One end of the center conductor 6 is connected to the electrode on the upper surface of the capacitive element 10 and the terminal electrode portion 16c. At this time, the heights of the terminal electrode portions 16b and 16c are configured to coincide with the heights of the electrodes on the upper surfaces of the capacitive elements 9 and 10, so that the connectivity of the center conductor is improved.
[0021]
And the permanent magnet 2 which applies a direct-current magnetic field to the ferrite disc 3 was positioned in the upper case 1, and the upper case 1 and the lower case 12 were joined, and the isolator was comprised.
[0022]
In the present embodiment, the permanent magnet 2 has a rectangular shape, is positioned on the inner surface of the upper case 1, and the periphery of the side surface of the permanent magnet 2 and the inner surface of the upper case are arranged in a close contact state. By making the permanent magnet into a rectangular shape and being in close contact with the upper case, the permanent magnet can be disposed throughout the case, which is advantageous for downsizing.
[0023]
The permanent magnet 2 of this embodiment will be described below.
SrCO ₃ and Fe ₂ O ₃ were blended so as to have a basic composition of SrO · nFe ₂ O ₃ (n = 5.9), wet-mixed, and then calcined at 1250 ° C. for 2 hours in the air. The calcined powder was dry pulverized with a roller mill to obtain coarse powder. Thereafter, wet pulverization was performed with an attritor to obtain a slurry containing fine powder having an average particle diameter of about 0.8 μm. At the beginning of the coarse powder pulverization step, 2.5 wt% La ₂ O ₃ and 1.2 wt% Co ₃ O ₄ are added based on the weight of the coarse powder, and 2-8 wt% Fe ₃ O ₄ (magnetite) was added. Furthermore, at the initial stage of the coarse pulverization step, 0.1% by weight of SrCO ₃ , 1.0% by weight of CaCO ₃ and 0.3% by weight of SiO ₂ are used as sintering aids based on the weight of the coarse powder. Added. Each obtained fine powder slurry was wet-molded in a magnetic field of 10 kOe, and the obtained molded body was sintered at 1210 to 1230 ° C. for 2 hours. The basic composition of the obtained sintered body substantially corresponds to the following composition formula.
(Sr _1-x La _x ) O · n [(Fe _1-y Co _y ) ₂ O ₃ ]
x = 0.15, y = x / 2n, n = 5.32 to 5.67
Table 1 shows the magnetic characteristics of this example magnet and the conventional magnet.
[0024]
[Table 1]

[0025]
Thus, the permanent magnet used for this invention has a magnetic characteristic higher than before.
[0026]
According to this example, a very small and thin lumped constant type nonreciprocal circuit device of 5 mm × 5 mm × height 2 mm could be obtained. Further, FIG. 2 shows an insertion loss characteristic of the embodiment, and FIG. 3 shows an isolation characteristic. According to the present example, the 2.4 GHz band lumped constant type nonreciprocal circuit device could be configured to be very small, such as 5 mm × 5 mm × height 2 mm.
In addition, the present invention is effective even at a frequency of 2 GHz or less. In particular, according to the present invention, it is a technique effective for achieving a thin lumped constant type nonreciprocal circuit device having a height of 2 mm or less.
[0027]
Although the above embodiment has been described with an isolator, it is needless to say that the circulator can be configured with the same technique. Further, if the permanent magnet of the present invention satisfies the basic composition described above, a lumped-constant nonreciprocal circuit device having desired characteristics can be obtained as in the above embodiment. Of course, the permanent magnet may be disk-shaped.
[0028]
【The invention's effect】
According to the present invention, it is possible to reduce the size and thickness of a lumped constant nonreciprocal circuit element, and it is possible to obtain a lumped constant nonreciprocal circuit element corresponding to a high frequency of 2 GHz or more.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an embodiment according to the present invention.
FIG. 2 is an insertion loss characteristic of an embodiment according to the present invention.
FIG. 3 is an isolation characteristic of an embodiment according to the present invention.
FIG. 4 is an exploded perspective view of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upper case 2 Permanent magnet 3 Ferrite disc 4, 5, 6 Center conductor 7 Resin case 8, 9, 10 Capacitor element 11 Resistor element 12 Lower case 13a Center conductor part recessed part 13b, 13c, 13d Capacitor element recessed part 14a Ground Electrode 15a, 15b, 15c External terminal 16a, 16b, 16c Terminal electrode part 17 Resistance element penetration recessed part 18 Recessed part

Claims (1)

A plurality of central conductors, a ferrimagnetic body disposed in proximity to the central conductor, a capacitive component connected to the central conductor, and a permanent magnet that applies a DC magnetic field to the ferrimagnetic body, and these are provided with a magnetic yoke a lumped-constant nonreciprocal circuit device formed by arranging in a metal casing also serving as the permanent _{magnet, (a 1-x R x} ) O · n [(Fe 1-y M y) 2 O 3] ( Atomic ratio) (A is Sr and / or Ba, R is at least one rare earth element including Y, and M is at least one selected from the group consisting of Co, Mn, Ni and Zn), 0.01 ≦ x ≦ 0.4, [x / (2.6n)] ≦ y ≦ [x / (1.6n)], 5 ≦ n ≦ 5.67 Concentration characterized by using ferrite magnets with a plumbite type crystal structure Constant nonreciprocal circuit element.

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