JP2001189585A - Electromagnetic wave absorber utilizing high-order absorption peak - Google Patents
Electromagnetic wave absorber utilizing high-order absorption peakInfo
- Publication number
- JP2001189585A JP2001189585A JP37451599A JP37451599A JP2001189585A JP 2001189585 A JP2001189585 A JP 2001189585A JP 37451599 A JP37451599 A JP 37451599A JP 37451599 A JP37451599 A JP 37451599A JP 2001189585 A JP2001189585 A JP 2001189585A
- Authority
- JP
- Japan
- Prior art keywords
- electromagnetic wave
- wave absorber
- thickness
- absorption
- peak
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/28—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder dispersed or suspended in a bonding agent
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- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Hard Magnetic Materials (AREA)
- Soft Magnetic Materials (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ミリ波（３０〜１
００ＧＨｚ）の周波数領域で使用する電磁波吸収体に関
する。The present invention relates to a millimeter wave (30 to 1).
(00 GHz) in the frequency range.
【０００２】[0002]
【従来の技術】軟磁性金属の粉末をゴムまたはプラスチ
ックのマトリクス中に分散させてシート状に成形してな
る電磁波吸収体が、さまざまな電子機器において、外部
からの電磁波の影響を遮断するため、外部への電磁波の
放射を防止するため、また機器内部での相互干渉を抑制
するため、広く用いられている。これらの電磁波吸収シ
ートは、吸収すべき電磁波の周波数がどのあたりである
かに応じて、吸収性能の指標であるリターンロスＲＬ
（反射減衰率）がその周波数で最大になるように、充填
する軟磁性金属粉末の形状・粒子サイズ、充填率、厚さ
などの因子を選択して設計され、製作されている。2. Description of the Related Art An electromagnetic wave absorber formed by dispersing a soft magnetic metal powder in a rubber or plastic matrix and forming it into a sheet shape is used in various electronic devices to block the influence of external electromagnetic waves. It is widely used to prevent radiation of electromagnetic waves to the outside and to suppress mutual interference inside the device. These electromagnetic wave absorbing sheets have a return loss RL, which is an index of absorption performance, depending on the frequency of the electromagnetic wave to be absorbed.
It is designed and manufactured by selecting factors such as the shape and particle size, filling rate, and thickness of the soft magnetic metal powder to be filled so that (reflection attenuation rate) becomes maximum at that frequency.
【０００３】一方、電子機器に関する技術が進展し、最
近ではミリ波の領域（３０〜１００ＧＨｚ）に属する、
きわめて高い周波数の電波が使用されるようになり、そ
れに伴って、この領域において使用するのに適した電磁
波吸収体が要求されるようになってきた。On the other hand, the technology related to electronic equipment has been advanced, and recently, it belongs to the millimeter wave region (30 to 100 GHz).
Very high frequency radio waves have been used, and accordingly, an electromagnetic wave absorber suitable for use in this region has been required.
【０００４】しかし、このような高い周波数領域で所望
の吸収ピークを有する電磁波吸収体を、従来の軟磁性金
属粉末／マトリクス技術によって製造しようとすると、
十分なリターンロスを稼げないという問題があった。そ
の理由は、電磁波吸収体の吸収ピーク周波数は、上記の
ように軟磁性金属粉末の充填率、厚さなどの因子によっ
て決定されるところ、厚くするとピークが低周波側にシ
フトしてしまい、極端に薄くしないと、ミリ波の領域に
吸収ピークが位置しないからである。電磁波吸収体の厚
さが薄ければ、リターンロスは実用性のあるレベルに達
しない。リターンロスのレベルに対する要求が低い場合
であっても、薄いシートの製造は高い精度で行なうこと
が困難で、少しの厚さのバラツキや変化が電磁波吸収体
の特性を大きく変えてしまう。However, when an electromagnetic wave absorber having a desired absorption peak in such a high frequency region is to be manufactured by a conventional soft magnetic metal powder / matrix technique,
There was a problem that a sufficient return loss could not be earned. The reason is that the absorption peak frequency of the electromagnetic wave absorber is determined by factors such as the filling rate and the thickness of the soft magnetic metal powder as described above. This is because the absorption peak will not be located in the millimeter wave region unless it is made thinner. If the thickness of the electromagnetic wave absorber is thin, the return loss does not reach a practical level. Even when the demand for the level of the return loss is low, it is difficult to manufacture a thin sheet with high accuracy, and a small variation or change in the thickness greatly changes the characteristics of the electromagnetic wave absorber.
【０００５】発明者等は、電磁波吸体における吸収ピー
クが、その電磁波吸収体の示す透磁率（μ）、誘電率
（ε）および厚さ（ｔ）によって決定される周波数間隔
で繰り返し現れるという事実に着目し、第二次ピーク以
降の高次ピークを利用することを企てて研究の結果、高
次ピークの周波数においてもまた、十分なリターンロス
が得られることを確認し、ときには、むしろ第一次ピー
クよりも高いリターンロスが実現することを見出した。[0005] The inventors have reported that the absorption peak of an electromagnetic wave absorber repeatedly appears at frequency intervals determined by the magnetic permeability (μ), dielectric constant (ε) and thickness (t) of the electromagnetic wave absorber. As a result of research aiming to use higher order peaks after the second peak, it was confirmed that sufficient return loss was also obtained at the frequency of the higher order peak. It has been found that a return loss higher than the primary peak is realized.
【０００６】[0006]
【発明が解決しようとする課題】本発明の目的は、上記
した発明者等の新しい知見を実用化し、軟磁性金属の粉
末をゴムまたはプラスチックのマトリクス中に分散させ
て製造する電磁波吸体であって、ミリ波の周波数領域の
中で所望の周波数に吸収ピークを有し、かつその周波数
におけるリターンロスが、実用上十分なレベルである２
０ｄＢ以上（９０％以上の吸収）に達する電磁波吸収体
を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic wave absorber manufactured by dispersing a soft magnetic metal powder in a rubber or plastic matrix, utilizing the above-mentioned new findings of the present inventors. In addition, it has an absorption peak at a desired frequency in the millimeter wave frequency range, and the return loss at that frequency is a level sufficient for practical use.
An object of the present invention is to provide an electromagnetic wave absorber reaching 0 dB or more (absorption of 90% or more).
【０００７】[0007]
【課題を解決するための手段】本発明の電磁波吸収体
は、軟磁性金属の粉末をゴムまたはプラスチックのマト
リクス中に分散させてなる電磁波吸収体であって、ミリ
波（３０〜１００ＧＨｚ）帯域で使用するものにおい
て、その電磁波吸収シートの示す透磁率（μ）、誘電率
（ε）および厚さ（ｔ）によって決定される周波数間隔
で繰り返し現れる吸収ピークのうち、第二次ピーク以降
の高次ピークを利用して厚さ０．５mm以上を確保するこ
とにより、２０ｄＢ以上のリターンロスを実現したもの
である。The electromagnetic wave absorber of the present invention is an electromagnetic wave absorber obtained by dispersing a soft magnetic metal powder in a rubber or plastic matrix, and is used in a millimeter wave (30 to 100 GHz) band. Among the absorption peaks that appear repeatedly at frequency intervals determined by the magnetic permeability (μ), the dielectric constant (ε), and the thickness (t) of the electromagnetic wave absorbing sheet, the higher order after the second peak is used. By using the peak to secure a thickness of 0.5 mm or more, a return loss of 20 dB or more is realized.
【０００８】[0008]
【発明の実施形態】軟磁性金属の粉末としては、もちろ
ん任意のものが使用できるが、この種の電磁波吸収体に
常用されている、Ｆｅ−１３Ｃｒ合金またはＦｅ−７Ｃ
ｒ−９Ａｌ合金の粉末が好適に使用できる。ミリ波帯に
おいては、粉末の形状は、誘電率のコントロールを容易
にするという観点から、球状粉が好ましい。マトリクス
材料としては、シリコンゴム、塩素化ポリエチレンゴ
ム、アクリロニトリル・ブタジエン・スチレン共重合
体、ポリフェニレンサルファイドなどが適当である。DESCRIPTION OF THE PREFERRED EMBODIMENTS As the soft magnetic metal powder, any powder can be used. Of course, an Fe-13Cr alloy or Fe-7C alloy commonly used in this type of electromagnetic wave absorber is used.
An r-9Al alloy powder can be suitably used. In the millimeter wave band, the shape of the powder is preferably a spherical powder from the viewpoint of facilitating control of the dielectric constant. Suitable matrix materials include silicone rubber, chlorinated polyethylene rubber, acrylonitrile-butadiene-styrene copolymer, polyphenylene sulfide, and the like.
【０００９】金属粉末充填率とシート厚さとの組み合わ
せを選択して第一次吸収ピークを決定する手法は、すで
に発明者らが確立し、別途提案している（特願平１１−
３１４５４号）。その手法は、所定のマトリクス物質中
に所定の軟磁性金属の粉末を種々の充填率で分散させた
電磁波吸収体について、電磁波吸収能のピークを位置さ
せようとする周波数における透磁率（μ）および誘電率
（ε）を各充填率ごとに測定してデータベースを構築し
ておき、そのデータに基づき、次式で表される リターンロス（反射減衰量）ＲＬの値 ＲＬ＝２０LogΓ Γ（反射係数）＝（Ｚin−Ｚ0）／（Ｚin＋Ｚ0） Ｚin＝Ｚ0√（μ／ε）×tanh［ｊ（２πｄ／λ）×（√（με））］ Ｚ0：空気中の特性インピーダンス ｄ：吸収体シートの厚さ λ：波長 が最大になる充填率および厚さを選択し、組み合わせて
電磁波吸収体を設計し、製造するというものである。The technique of determining the primary absorption peak by selecting a combination of the metal powder filling rate and the sheet thickness has already been established by the present inventors and has been separately proposed (Japanese Patent Application No. 11-110).
No. 31454). The method is based on a magnetic permeability (μ) at a frequency at which the peak of the electromagnetic wave absorbing capacity is to be located for an electromagnetic wave absorber in which a predetermined soft magnetic metal powder is dispersed in a predetermined matrix material at various filling rates. A database is constructed by measuring the dielectric constant (ε) for each filling factor, and based on the data, the value of the return loss (reflection loss) RL expressed by the following equation RL = 20LogΓ (reflection coefficient) = (Z in -Z 0 ) / (Z in + Z 0 ) Z in = Z 0 √ (μ / ε) × tanh [j (2πd / λ) × (√ (με))] Z 0 : Characteristics in air Impedance d: The thickness of the absorber sheet λ: The filling factor and the thickness that maximize the wavelength are selected and combined to design and manufacture an electromagnetic wave absorber.
【００１０】電磁波吸収体が示す吸収ピークは、上式に
おける tanh［ｊ×（２πｄ／λ）×√（εμ）］ が決定する周期（tanhは周期関数）にしたがって現れ
る。つまり、電磁波吸収体に使用した材料の誘電率
（ε）、透磁率（μ）および厚さ（ｔ）によって決定さ
れる。tanh［Ｘ］のＸの値が大きければ、周期すなわち
吸収ピーク周波数の間隔は狭く、Ｘの値が小さければ、
逆に間隔は広い。[0010] The absorption peak of the electromagnetic wave absorber appears in accordance with the period (tanh is a periodic function) determined by tanh [j × (2πd / λ) × √ (εμ)] in the above equation. That is, it is determined by the dielectric constant (ε), magnetic permeability (μ), and thickness (t) of the material used for the electromagnetic wave absorber. If the value of X in tanh [X] is large, the period, that is, the interval between absorption peak frequencies is narrow, and if the value of X is small,
Conversely, the interval is wide.
【００１１】通常は、第二次または第三次の吸収ピーク
を利用すればよいが、きわめて高い周波数においては、
もっと高次の吸収ピークを利用することが得策といえる
場合もある。本発明の実施にあたっては、吸収のピーク
を置こうとする周波数に、何次の吸収ピークを当てるか
をまず考え、その吸収ピークをもたらす電磁波吸収体の
物性、すなわち透磁率および誘電率を実現する金属粉末
充填率と厚さとの組み合わせを選択する。Normally, the secondary or tertiary absorption peak may be used, but at very high frequencies,
In some cases, it may be advisable to use higher absorption peaks. In practicing the present invention, first consider the order of the absorption peak to be applied to the frequency at which the absorption peak is to be placed, and realize the physical properties of the electromagnetic wave absorber that gives the absorption peak, that is, the magnetic permeability and the dielectric constant. Select a combination of metal powder filling rate and thickness.
【００１２】この手法は、一般に的確な設計が可能であ
るが、設計値と実際の製品の特性との間に若干のズレが
生じることがある。その場合は、必要により設計値を修
正して再度製造を試みる、試行錯誤を行なうべきことは
もちろんである。[0012] Although this method generally allows accurate design, there may be a slight deviation between the design value and the actual product characteristics. In such a case, it is a matter of course that trial and error in which the design values are corrected and the manufacture is attempted again if necessary.
【００１３】軟磁性金属の粉末とマトリクス材料との混
練および成形は、この分野で既知の技術にしたがって実
施することができる。電磁波吸収体の透磁率および誘電
率の測定は、ネットワークアナライザーに導波管を接続
して行なうことができ、この手法も既知である。リター
ンロスの測定は、おおよそ５０ＧＨｚを境界として、そ
れ以下の周波数領域では従来の手法で行なうことができ
るが、それ以上の周波数領域では、アンテナから放射さ
れる電波を吸収体に入射して測定する自由空間法を用い
る方が、測定誤差が小さくできて好ましい。The kneading and molding of the soft magnetic metal powder and the matrix material can be carried out according to techniques known in the art. The measurement of the magnetic permeability and the permittivity of the electromagnetic wave absorber can be performed by connecting a waveguide to a network analyzer, and this method is also known. The return loss can be measured by a conventional method in a frequency range below approximately 50 GHz as a boundary, but in a frequency range higher than 50 GHz, a radio wave radiated from an antenna is incident on an absorber and measured. It is preferable to use the free space method because the measurement error can be reduced.
【００１４】[0014]
【実施例】［比較例］軟磁性金属の粉末として水噴霧に
より製造したＦｅ−１３Ｃｒ合金の粉末（平均粒子径１
０μｍ）を使用し、マトリクス材料として塩素化ポリエ
チレンゴムを使用し、粉末充填率１０容積％、厚さ０．
３mmのシート状の電磁波吸収体を製造した。これは、第
一次吸収ピークが７６ＧＨｚに位置するように設計した
ものである。[Comparative Example] Fe-13Cr alloy powder (average particle size: 1) produced by water spraying as a soft magnetic metal powder
0 μm), chlorinated polyethylene rubber is used as the matrix material, the powder filling rate is 10% by volume, and the thickness is 0.1%.
A 3 mm sheet-like electromagnetic wave absorber was produced. This is designed so that the first absorption peak is located at 76 GHz.
【００１５】この電磁波吸収体についてリターンロスを
実測したところ、図１のグラフにみるとおりであった。
減衰はわずか６ｄＢ程度に止まり、電磁波吸収性能は不
充分であった。 ［実施例１］７６ＧＨｚにおいて２０ｄＢ以上の減衰を
実現すべく、第二次吸収ピークおよび第三次吸収ピーク
を利用した電磁波吸収体を、下記の条件で製造した。リ
ターンロスを実測して、図２の結果を得た。The return loss of this electromagnetic wave absorber was measured, as shown in the graph of FIG.
The attenuation was only about 6 dB, and the electromagnetic wave absorption performance was insufficient. [Example 1] In order to realize attenuation of 20 dB or more at 76 GHz, an electromagnetic wave absorber using a second absorption peak and a third absorption peak was manufactured under the following conditions. The return loss was measured, and the result of FIG. 2 was obtained.
【００１６】 高次吸収 充填率 厚 さ リターンロス ピーク （容積％） （mm） （ｄＢ） 第二次 ２４ １．０ ２５ 第三次 １６ １．９ ２８ ［実施例２］実施例１と同様に、軟磁性金属の粉末とし
てＦｅ−７Ｃｒ−９Ａｌ合金の粉末を、マトリクス材料
として塩素化ポリエチレンゴムを使用して、充填率を１
６容積％、厚さを１．６mmとすることによって、９５Ｇ
Ｈｚ付近に第三次吸収ピークを有するシート状の電磁波
吸収体を製造した。この電磁波吸収体のリターンロスを
実測した結果を、設計値とともに図３のグラフに示す。Higher-order absorption Filling rate Thickness Return loss peak (Volume%) (mm) (dB) Secondary 24 1.025 Tertiary 16 1.9 28 [Example 2] As in Example 1, Using Fe-7Cr-9Al alloy powder as the soft magnetic metal powder and chlorinated polyethylene rubber as the matrix material, the filling rate is 1
By setting the volume to 6% by volume and the thickness to 1.6 mm, 95 G
A sheet-like electromagnetic wave absorber having a tertiary absorption peak near Hz was manufactured. The results of the actual measurement of the return loss of the electromagnetic wave absorber are shown in the graph of FIG. 3 together with the design values.
【００１７】[0017]
【発明の効果】本発明に従い、軟磁性金属の粉末をゴム
またはプラスチックのマトリクス中へ充填してなるシー
ト状体をもって、ミリ波帯用電磁波吸収体を製造すれ
ば、第二次吸収ピーク以降の高次吸収ピークを利用する
ことにより、ミリ波帯（３０〜１００ＧＨｚ）で使用す
る電磁波吸収体においても、厚さ０．５mm以上を確保す
ることができるため、２０ｄＢ（すなわち９０％の吸
収）以上、好ましい例においては２５ｄＢから３０ｄＢ
に至るリターンロスが得られるから、実質上完全な電磁
波吸収が実現する。According to the present invention, if an electromagnetic wave absorber for a millimeter wave band is manufactured by using a sheet-like body in which a soft magnetic metal powder is filled in a rubber or plastic matrix, the second absorption peak and thereafter can be obtained. By utilizing the high-order absorption peak, a thickness of 0.5 mm or more can be ensured even in an electromagnetic wave absorber used in a millimeter wave band (30 to 100 GHz), so that 20 dB (ie, 90% absorption) or more 25 to 30 dB in a preferred example
, A substantially complete electromagnetic wave absorption is realized.
【００１８】本発明によって、これまで高性能の電磁波
吸収体が得られていなかったミリ波帯（３０〜１００Ｇ
Ｈｚ）の電磁波吸収が、容易に行なえるようになった。According to the present invention, a high-performance electromagnetic wave absorber (30 to 100 G) has not been obtained until now.
(Hz) can be easily absorbed.
【図１】 本発明の比較例において従来技術により製造
した、７６ＧＨｚ用の電磁波吸収体が示したリターンロ
スのグラフ。FIG. 1 is a graph of a return loss of an electromagnetic wave absorber for 76 GHz manufactured by a conventional technique in a comparative example of the present invention.
【図２】 本発明の実施例１において製造した、７６Ｇ
Ｈｚ用の電磁波吸収体が示したリターンロスのグラフ。FIG. 2 shows a graph of 76G manufactured in Example 1 of the present invention.
The return loss graph which the electromagnetic wave absorber for Hz showed.
【図３】 本発明の実施例２において製造した、９５Ｇ
Ｈｚ用の電磁波吸収体が示したリターンロスのグラフ。FIG. 3 shows 95G produced in Example 2 of the present invention.
The return loss graph which the electromagnetic wave absorber for Hz showed.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｆ 1/26 Ｈ０１Ｆ 1/14 Ｚ Ｆターム(参考） 4J002 AA001 AC001 BB241 CP031 DA086 DC006 FD206 GR00 5E040 AA11 AA19 BB03 BB06 CA13 NN01 NN04 NN06 NN15 5E041 AA11 AA19 BB03 BB06 CA06 NN01 NN04 NN06 NN14 NN15 5E321 BB32 BB53 GG11 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01F 1/26 H01F 1/14 Z F term (Reference) 4J002 AA001 AC001 BB241 CP031 DA086 DC006 FD206 GR00 5E040 AA11 AA19 BB03 BB06 CA13 NN01 NN04 NN06 NN15 5E041 AA11 AA19 BB03 BB06 CA06 NN01 NN04 NN06 NN14 NN15 5E321 BB32 BB53 GG11
Claims (4)
ックのマトリクス中に分散させてなる電磁波吸収体であ
って、ミリ波（３０〜１００ＧＨｚ）帯域で使用するも
のにおいて、その電磁波吸収体の示す透磁率（μ）、誘
電率（ε）および厚さ（ｔ）によって決定される周波数
間隔で繰り返し現れる吸収ピークのうち、第二次ピーク
以降の高次ピークを利用して厚さ０．５mm以上を確保す
ることにより、２０ｄＢ以上のリターンロスを実現した
電磁波吸収体。An electromagnetic wave absorber obtained by dispersing a soft magnetic metal powder in a rubber or plastic matrix, which is used in a millimeter wave (30 to 100 GHz) band. Of the absorption peaks repeatedly appearing at the frequency intervals determined by the magnetic susceptibility (μ), the dielectric constant (ε), and the thickness (t), the thickness of 0.5 mm or more is used by using the higher order peaks after the second peak. An electromagnetic wave absorber that achieves a return loss of 20 dB or more by securing it.
ｒ合金またはＦｅ−７Ｃｒ−９Ａｌ合金の粉末を使用
し、マトリクス材料としてシリコンゴムまたは塩素化ポ
リエチレンゴムを使用した請求項１の電磁波吸収体。2. A soft magnetic metal powder comprising Fe-13C
2. The electromagnetic wave absorber according to claim 1, wherein a powder of r alloy or Fe-7Cr-9Al alloy is used, and silicon rubber or chlorinated polyethylene rubber is used as a matrix material.
合金の粉末を、マトリクス材料として塩素化ポリエチレ
ンゴムを使用し、それぞれ下記の充填率および厚さを有
することによって、対応する高次吸収ピークを７６ＧＨ
ｚ付近に有する請求項２の電磁波吸収体。 充填率 厚 さ 高次吸収 リターンロス （容積％）（mm） ピーク （ｄＢ） ２４ １．０ 第二次 ２９ １６ １．９ 第三次 ２８ 3. A soft magnetic metal powder comprising Fe-13Cr.
The corresponding higher absorption peaks of the alloy powders were increased to 76 GH by using chlorinated polyethylene rubber as matrix material and having the following filling rates and thicknesses, respectively.
3. The electromagnetic wave absorber according to claim 2, wherein the electromagnetic wave absorber is provided near z. Filling rate Thickness Higher order absorption Return loss (% by volume) (mm) Peak (dB) 24 1.0 Secondary 29 16 1.9 Tertiary 28
合金の粉末を、マトリクス材料として塩素化ポリエチレ
ンゴムを使用し、充填率を１６容積％、厚さを１．６mm
とすることによって、９５ＧＨｚ付近に第三次吸収ピー
クを有する請求項２の電磁波吸収体。4. A soft magnetic metal powder comprising Fe-13Cr
Alloy powder, chlorinated polyethylene rubber as matrix material, filling rate 16% by volume, thickness 1.6mm
The electromagnetic wave absorber according to claim 2, having a third absorption peak near 95 GHz.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37451599A JP2001189585A (en) | 1999-12-28 | 1999-12-28 | Electromagnetic wave absorber utilizing high-order absorption peak |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37451599A JP2001189585A (en) | 1999-12-28 | 1999-12-28 | Electromagnetic wave absorber utilizing high-order absorption peak |
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|---|---|
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Family
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|---|---|---|---|
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| US20180103564A1 (en) * | 2016-10-11 | 2018-04-12 | Daido Steel Co., Ltd. | Electromagnetic wave absorbing body and method for manufacturing electromagnetic wave absorbing body |
| JP2018067715A (en) * | 2017-10-30 | 2018-04-26 | 株式会社東芝 | Electromagnetic wave absorber |
| CN113436824A (en) * | 2021-07-07 | 2021-09-24 | 上海圣石生物医学科技有限公司 | Magnetic wave-absorbing material, preparation method, application and health-care product thereof |
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