JPH0632417B2 - Radio wave absorber - Google Patents
Radio wave absorberInfo
- Publication number
- JPH0632417B2 JPH0632417B2 JP63245235A JP24523588A JPH0632417B2 JP H0632417 B2 JPH0632417 B2 JP H0632417B2 JP 63245235 A JP63245235 A JP 63245235A JP 24523588 A JP24523588 A JP 24523588A JP H0632417 B2 JPH0632417 B2 JP H0632417B2
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- Prior art keywords
- radio wave
- fiber
- wave absorber
- fibers
- thickness
- Prior art date
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Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、電波（特にマイクロ波、ミリ波、サブミリ波
等）を吸収する電波吸収体に関するものである。The present invention relates to a radio wave absorber that absorbs radio waves (especially microwaves, millimeter waves, submillimeter waves, etc.).
［従来技術］ 従来、上記波長帯で使用される電波吸収体としては、馬
の尻尾の毛と椰子の繊維を絡ませて接着剤で固定し、こ
れにカーボンを被覆したマット状のものが知られてい
る。椰子の繊維を馬の尻尾の毛に混ぜるのは、馬の毛は
供給量が少なく入手困難でそれを補充するのに椰子の繊
維が最適であり、また電波吸収特性を向上させるため
に、空間部分を多くするのに都合が良いからである。[Prior Art] Conventionally, as a radio wave absorber used in the above-mentioned wavelength band, a mat-like one is known in which hair of a horse's tail and fibers of a palm are entwined and fixed with an adhesive, and carbon is coated on this. ing. Mixing coconut fiber with horse tail hair is because horse hair is scarcely available and is difficult to obtain, and coconut fiber is the best way to replenish it. This is because it is convenient to increase the number of parts.
この種の繊維をランダムに集合させた電波吸収体は、例
えば送信アンテナとしてパラボラアンテナの放物面反射
鏡の側面に取り付けて、隣接のパラボラアンテナとの干
渉を防止するために使用されている。この場合にはアン
テナによって一方向に放射される電波の他に、回折によ
って放物面反射器の後側に回り込む電波があるが、これ
は電波エネルギー損失や他の電波と干渉し合う原因にな
るので、これを防ぐためにマット状の電波吸収体によっ
て回折波を吸収する。A radio wave absorber in which fibers of this kind are randomly gathered is attached to a side surface of a parabolic reflector of a parabolic antenna as a transmitting antenna, for example, and is used to prevent interference with an adjacent parabolic antenna. In this case, in addition to radio waves radiated in one direction by the antenna, there are radio waves that go around behind the parabolic reflector due to diffraction, but this causes radio wave energy loss and interference with other radio waves. Therefore, in order to prevent this, the diffracted wave is absorbed by the mat-shaped wave absorber.
［発明が解決しようとする課題］ ところで、馬の尻尾の毛及び椰子の繊維は天然のもので
あるから、品質の同じものを揃えるのが困難であり、そ
の供給量から入手困難である。[Problems to be Solved by the Invention] By the way, since the hairs of the horse's tail and the fibers of the palm are natural, it is difficult to prepare the same quality fibers, and it is difficult to obtain them due to the supply amount.
また、馬の尻尾の毛及び椰子の繊維は、毛や繊維の太さ
には多少の違いはあるにせよ巨視的にみた場合ほぼ一種
類しかなく、両者からなる電波吸収体を構成する繊維は
高々両者の２種類だけである。一般的に、繊維の太さの
種類に限定があると電波吸収帯域も狭くなる。従って、
広い電波吸収帯域幅を得ようとするなら多種類の太さの
繊維からなることが望ましい。Also, the hair of the tail of the horse and the fibers of the palm are only one kind when viewed macroscopically, although there are some differences in the thickness of the hair and the fibers, and the fibers that make up the electromagnetic wave absorber composed of both are Only at most two types. In general, if there is a limitation on the type of fiber thickness, the electromagnetic wave absorption band also narrows. Therefore,
If a wide electromagnetic absorption bandwidth is to be obtained, it is desirable that the fibers are made of various kinds of thickness.
さらに、馬の尻尾の毛及び椰子の繊維からなる従来の電
波吸収体、とりわけ椰子の繊維は炭化水素よりなるもの
であるから、その表面にカーボンが付着し難いという特
性を有しており、それがためこれら毛及び繊維には均一
な厚さのカーボン被覆を形成し難い。しかして、これら
毛及び繊維のカーボン被覆の厚さにムラがあると、極超
短波などの所定の波長帯が全帯域にわたって一様なレベ
ルで吸収されないので電波吸収体としては好ましいもの
ではにない。Furthermore, conventional radio wave absorbers made of horse tail hair and palm fibers, especially palm fibers are made of hydrocarbons, and therefore have the property that carbon is difficult to adhere to their surfaces. Therefore, it is difficult to form a carbon coating having a uniform thickness on these hairs and fibers. However, if the thickness of the carbon coating of these hairs and fibers is uneven, a predetermined wavelength band such as ultra-high frequency wave is not absorbed at a uniform level over the entire band, which is not preferable as a radio wave absorber.
上記のような実情から、本発明者らはマット状の電波吸
収体では、電波吸収特性の向上を計るには、種々の太さ
の繊維からなること、繊維の表面に均一なカーボン被覆
が形成されていることなどが挙げられることに着目し
た。さらにより良好な電波吸収特性を得るには、電波吸
収体を、電波の入射面において反射波を生じさせない構
成とする必要があることを見出した。From the above-mentioned circumstances, the present inventors have found that the mat-shaped electromagnetic wave absorber should be composed of fibers of various thicknesses in order to improve the electromagnetic wave absorption characteristics, and that a uniform carbon coating is formed on the surface of the fiber. We paid attention to what is being done. It has been found that in order to obtain better radio wave absorption characteristics, the radio wave absorber must be configured so as not to generate reflected waves on the incident surface of radio waves.
本発明の目的は、一本の繊維の太さが均一であり、多種
の太さの繊維を有し、該繊維に一定厚さのカーボン薄膜
を形成すると共に、反射波を生じさせないように構成し
た電波吸収体を提供することにある。An object of the present invention is to have one fiber having a uniform thickness and having fibers of various thicknesses, forming a carbon thin film having a constant thickness on the fibers, and not forming a reflected wave. To provide a radio wave absorber.
［課題を解決するための手段］ 前記目的を達成するために、本発明の電波吸収体は、カ
ーボンで被覆された多種類の太さの極性ポリマーからな
る繊維を、各種繊維が少なくとも５重量％含有されるよ
うに互いに絡ませると共に互いに結合させて形成された
マット状繊維集合体からなる電波吸収体であって、該繊
維集合体は、その厚さ方向に繊維密度を変化させている
ことを特徴とするものである。[Means for Solving the Problems] In order to achieve the above-mentioned object, the electromagnetic wave absorber of the present invention comprises a fiber made of polar polymers of various thicknesses coated with carbon, and at least 5% by weight of each fiber. A radio wave absorber made of a mat-shaped fiber aggregate formed by being entangled with each other and bound together so that the fiber aggregate has a fiber density varied in the thickness direction. It is a feature.
［発明の構成］ 本発明の電波吸収体は、極性ポリマーからなり且つカー
ボン被覆を有する繊維を互いに絡ませたマット状のもの
で、従来のように馬の尻尾の毛や椰子の繊維等の天然繊
維ではなく人工繊維を使用しているので、各々の繊維は
それぞれ均一な太さを有し且つ種々の太さの繊維が容易
に得られ、しかも同一の品質の繊維を使用することが可
能なためカーボン被覆の厚さも均一にすることができ
る。[Structure of the Invention] The electromagnetic wave absorber of the present invention is a mat-like material in which fibers made of a polar polymer and having a carbon coating are entangled with each other, and conventional natural fibers such as horse tail hair and palm fiber. Since artificial fibers are used instead, each fiber has a uniform thickness, fibers of various thicknesses can be easily obtained, and it is possible to use fibers of the same quality. The carbon coating thickness can also be uniform.
本発明で使用される極性ポリマーとしては特に制限はな
く、ポリ塩化ビニリデン、ナイロン、ポリエステル、ア
クリルなどが例示される。またカーボン被覆は、カーボ
ン及びバインダーとしてのポリ塩化ビニル、ポリ酢酸ビ
ニルなどの接着剤を適当な溶媒、例えばトルエン、キシ
レンなどの炭化水素やメタノール、エタノールなどのア
ルコールに溶解又は分散させたものをスプレー塗布など
の手段にて塗布することによって行われる。なお、絡ま
せた繊維はそのままの状態ではほぐれてしまう可能性が
あるので、例えば接着剤等で解離しないよう結合させて
おく必要がある。接着方法は任意であるが、好適な方法
としては例えば繊維を絡ませた状態のマット体にスプレ
ー接着剤を噴射し、繊維同士の重合部において接着を図
る方法等が挙げられる。The polar polymer used in the present invention is not particularly limited, and examples thereof include polyvinylidene chloride, nylon, polyester, acrylic and the like. The carbon coating is sprayed by dissolving or dispersing carbon and an adhesive such as polyvinyl chloride or polyvinyl acetate as a binder in a suitable solvent, for example, hydrocarbon such as toluene or xylene, or alcohol such as methanol or ethanol. It is performed by applying by means such as application. Since the entangled fibers may be loosened as they are, it is necessary to bond them with an adhesive or the like so as not to dissociate them. The method of adhesion is arbitrary, but as a suitable method, for example, a method of spraying a spray adhesive to a mat body in which fibers are entangled to bond the fibers at a polymerized portion of the fibers can be mentioned.
また、マット状繊維集合体は多種類の太さの繊維で構成
されていると共に、一つの太さの繊維が５重量％以上含
有されていることが、当該吸収体の電波吸収帯域を広く
し、かつ各帯域における電波吸収率を良好とさせる点で
必要である。言うまでもなく、広帯域の電波を吸収させ
ようとする場合には、繊維の太さの種類を増加せしめて
マット状繊維集合体を構成すれば良い。なおカーボン被
覆の厚さは通常５〜５０μｍ、好ましくは１０〜３０μ
ｍとすれば良い。Further, the mat-shaped fiber aggregate is composed of fibers of various thicknesses, and the fact that the fiber of one thickness is contained in an amount of 5% by weight or more expands the electromagnetic absorption band of the absorber. In addition, it is necessary to improve the radio wave absorption rate in each band. Needless to say, when it is desired to absorb a broadband radio wave, the mat-like fiber aggregate may be formed by increasing the types of fiber thickness. The thickness of the carbon coating is usually 5 to 50 μm, preferably 10 to 30 μm.
It should be m.
一方、広帯域に優れた電波吸収特性を得るためには、電
波吸収体に入射する電波を、電波吸収体の入射面におい
て反射させないようにする必要がある。そこで本発明に
おいては、マット状繊維集合体の厚さ方向の繊維密度を
変化させることにより、広帯域の電波が吸収し得るよう
にしている。すなわちマット状繊維集合体の一面の繊維
密度を粗として減衰を少なくし、他面を密として減衰を
大きくし、前記粗面を電波入射方向に向けて配置するこ
とにより、電波の入射面における反射を少なくして電波
を電波吸収体の内部へ取り込み易くすると共に、その内
部において電波が良好に吸収し得るようにしている。一
般に、電波が空間を伝搬する場合、急激に導電度が変化
する点に遭遇すると電波はその点で反射され易くなる。
電波吸収体も導電体であるため、電波を反射する作用も
有すると考えられる。而して繊維密度が一定な吸収体で
あると、電波を反射してしまう度合は大きくなる。そこ
で本発明では、電波入射面の導電度を低くして（繊維密
度を粗として）空気との導電度の差を小さくし、電波の
反射を極力抑制するようにしたものである。On the other hand, in order to obtain excellent radio wave absorption characteristics in a wide band, it is necessary to prevent the radio waves entering the radio wave absorber from being reflected by the incident surface of the radio wave absorber. Therefore, in the present invention, by changing the fiber density in the thickness direction of the mat-like fiber assembly, it is possible to absorb radio waves in a wide band. That is, the fiber density of one surface of the mat-shaped fiber aggregate is made coarse to reduce the attenuation, the other surface is made dense to increase the attenuation, and the rough surface is arranged in the radio wave incident direction to reflect the radio wave on the incident surface. Is reduced so that the radio waves can be easily taken into the radio wave absorber, and the radio waves can be favorably absorbed inside the absorber. In general, when a radio wave propagates in space, when it encounters a point where the conductivity changes abruptly, the radio wave is likely to be reflected at that point.
Since the radio wave absorber is also a conductor, it is considered to have a function of reflecting radio waves. Thus, if the absorber has a constant fiber density, the degree of reflection of radio waves increases. Therefore, in the present invention, the conductivity of the radio wave incident surface is lowered (the fiber density is made coarse) to reduce the difference in conductivity with air, and the reflection of radio waves is suppressed as much as possible.
なお、本発明の電波吸収体の厚さは任意であるが、通常
厚みは最下限吸収周波数の波長の１／２とされる。例え
ば、３GHz以上の電波を吸収させる場合は、その波長は
１００mmであるので、厚さを５０mmとすれば良い。The thickness of the radio wave absorber of the present invention is arbitrary, but the thickness is normally set to 1/2 of the wavelength of the lowest absorption frequency. For example, when absorbing a radio wave of 3 GHz or more, the wavelength is 100 mm, so the thickness may be 50 mm.
［実施例］ 以下、本発明の電波吸収体を実施例に基づいて具体的に
説明する。[Examples] Hereinafter, the radio wave absorber of the present invention will be specifically described based on Examples.
実施例 第１図は本発明の電波吸収体の１ブロックの外観を示
す。電波吸収体は各種太さの繊維Ｆがランダムに絡みあ
ったマット状繊維集合体からなり、繊維Ｆはほぐれない
ように接着剤による結合部１にて互に結合され、且つカ
ーボンで被覆されている。本実施例では、繊維Ｆは0.1m
m、0.15mm、0.2mm、0.25mm、0.3mm、0.4mm
、0.7mm、1.0mmの８種類のものを用い、厚さ５０
mm、縦×横＝３００mm×３００mmの試料を作成した。な
お繊維Ｆの密度は、電波入射側の比重を０．０３ｇ／cm
3、背面側を０．０６ｇ／cm3となるよう連続的に変化さ
せた。Example FIG. 1 shows the appearance of one block of the radio wave absorber of the present invention. The radio wave absorber is composed of a mat-shaped fiber aggregate in which fibers F of various thicknesses are randomly entwined, and the fibers F are bonded to each other at a bonding portion 1 by an adhesive so as not to be loosened, and are covered with carbon. There is. In this embodiment, the fiber F is 0.1 m
m, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.4mm
, 0.7mm, 1.0mm, 8 types, thickness 50
mm, length × width = 300 mm × 300 mm samples were prepared. The density of the fiber F is 0.03 g / cm
3 , the back side was continuously changed to 0.06 g / cm 3 .
各繊維Ｆは平均２５μｍ厚のカーボン被覆を有し、従っ
て電波吸収体としては一定の抵抗値を有する導電性にな
っている。例えば本実施例で作成した電波吸収体は、中
央部において５０mm間の抵抗をテスターで測定した時２
〜４ｋΩに設定されている。Each fiber F has a carbon coating with an average thickness of 25 μm, and is therefore electrically conductive as a radio wave absorber having a constant resistance value. For example, the electromagnetic wave absorber prepared in this example has a resistance of 50 mm at the center when measured with a tester.
It is set to ~ 4 kΩ.
かかる電波吸収体は、人工繊維で構成されているため繊
維の一本一本がそれぞれ均一な太さで、繊維が極性を有
するポリマーであるためカーボンも付着し易く、カーボ
ンの被覆厚さも一様である。しかも電波入射方向の繊維
密度を粗としているため、電波の反射度合は緩和され
る。従って、電波吸収も目的の波長帯域（特に極超短
波）にわたって一定のレベルで行なわれる。Since such a radio wave absorber is made of artificial fiber, each fiber has a uniform thickness, and since the fiber is a polymer having polarity, carbon easily adheres and the carbon coating thickness is uniform. Is. Moreover, since the fiber density in the radio wave incident direction is coarse, the degree of reflection of radio waves is relaxed. Therefore, radio wave absorption is also performed at a constant level over the target wavelength band (especially, ultrashort waves).
次に、第１図に示した電波吸収体の製造方法を述べる。Next, a method for manufacturing the electromagnetic wave absorber shown in FIG. 1 will be described.
基材となる極性ポリマーよりなる繊維として各太さが、
0.1mm、0.15mm、0.2mm、0.25mm、0.
3mm、0.4mm、0.7mm、1.0mmの繊維を用意
する。これら各種繊維を、５重量％、１０重量％、
１５重量％、１５重量％、１５重量％、１５重
量％、１０重量％、１５重量％になるように絡ま
せ、電波吸収体の比重を電波入射側０．０３ｇ／cm3、
その背面側０．０６ｇ／cm3となるようにマット状体を
形成した後に、該マット状体に塩化ビニリデン系バイン
ダーからなる接着剤をスプレーで塗布して各繊維を接着
・固定し、しかる後希釈液としてのトルエンとポリ塩化
ビニルのバインダー入りカーボン塗料を重量比で１：２
に溶解して製造したカーボン塗料をスプレー塗布して乾
燥することにより、第１図の電波吸収体を製造した。Each thickness as a fiber made of polar polymer as a base material,
0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.
Prepare 3 mm, 0.4 mm, 0.7 mm, and 1.0 mm fibers. 5% by weight, 10% by weight of these various fibers,
Entangled so as to be 15% by weight, 15% by weight, 15% by weight, 15% by weight, 10% by weight, 15% by weight, and the specific gravity of the electromagnetic wave absorber was 0.03 g / cm 3 on the incident side of the electromagnetic wave.
After forming a mat-like body so that the back side has a weight of 0.06 g / cm 3 , an adhesive consisting of a vinylidene chloride-based binder is spray-applied to the mat-like body to bond and fix the respective fibers. Carbon paint containing a binder of toluene and polyvinyl chloride as a diluting liquid in a weight ratio of 1: 2
The radio wave absorber shown in FIG. 1 was manufactured by spray-coating a carbon paint prepared by dissolving it on and spray-drying it.
かくして製造した電波吸収体を、第２図に示すような測
定系にて電波吸収特性を評価した。図において、供試電
波吸収体５の裏面（繊維密度が密の面）には金属板４が
敷設され、供試電波吸収体５の表面（繊維密度が粗の
面）に向けてホーンアンテナ２、２′が配置されてい
る。ここでホーンアンテナ２は送信Ｔ側、ホーンアンテ
ナ２′は受信Ｒ側とされている。なお３はホーンアンテ
ナ２′が受信した電波を検出する検波器である。かかる
構成で、ホーンアンテナ２から供試電波吸収体５に向け
て発した電波が、金属板４に反射してホーンアンテナ
２′へ戻ってくる度合、すなわち反射減衰量を2.8〜4.4
GHzの周波数帯において調査した。The electromagnetic wave absorber thus manufactured was evaluated for electromagnetic wave absorption characteristics by a measurement system as shown in FIG. In the figure, a metal plate 4 is laid on the back surface of the sample electromagnetic wave absorber 5 (the surface having a high fiber density), and the horn antenna 2 is directed toward the surface of the sample electromagnetic wave absorber 5 (the surface having a coarse fiber density). 2'is arranged. Here, the horn antenna 2 is on the transmitting T side, and the horn antenna 2'is on the receiving R side. Reference numeral 3 is a detector for detecting the radio wave received by the horn antenna 2 '. With such a configuration, the degree to which the radio wave emitted from the horn antenna 2 to the sample radio wave absorber 5 is reflected by the metal plate 4 and returned to the horn antenna 2 ', that is, the return loss is 2.8 to 4.4.
The survey was conducted in the GHz frequency band.
比較例 上記実施例と同種の各種繊維を同比率で絡ませ、比重が
０．０５ｇ／cm3の一定繊維密度として、厚さ５０mm、
縦×横＝３００mm×３００mmの試料を作成した。なお繊
維には前記実施例と同様にしてカーボン被覆が施され、
試料の中央部において５０mm間の抵抗をテスターで測定
した時２〜４ｋΩに設定した。Comparative Example Various fibers of the same kind as in the above example were entangled at the same ratio to give a constant fiber density of 0.05 g / cm 3 and a thickness of 50 mm,
A sample of length × width = 300 mm × 300 mm was prepared. The fibers are coated with carbon in the same manner as in the above example,
The resistance of 50 mm at the center of the sample was set to 2 to 4 kΩ when measured with a tester.
かくして製造した供試電波吸収体を、上記と同様に第２
図に示す測定系で2.8〜4.4GHzの周波数帯において反射
減衰量を調査した。The test electromagnetic wave absorber manufactured in this way was used for the second test as described above.
Using the measurement system shown in the figure, the return loss was investigated in the frequency band of 2.8 to 4.4 GHz.
第３図は上記実施例及び比較例にて製作した試料の電波
吸収特性を示している。この図からも明らかなように、
いずれの周波数の電波も反射減衰量は２０dB以上であ
り、極めて良好な電波吸収体であることが確認された。
また比較例と対比して明らかなように、繊維密度を変化
させた本発明品は、繊維密度一定の比較例品に比べても
優れた電波吸収特性を有することが確認された。FIG. 3 shows the electromagnetic wave absorption characteristics of the samples manufactured in the above-mentioned examples and comparative examples. As is clear from this figure,
It was confirmed that the radio wave of any frequency had a return loss of 20 dB or more, and was an extremely good radio wave absorber.
Further, as is clear from comparison with the comparative example, it was confirmed that the product of the present invention in which the fiber density was changed had excellent electromagnetic wave absorption characteristics even when compared with the comparative product having a constant fiber density.
なお図示はしていないが、4.4GHz以上の周波数帯におい
ては、本実施例品及び比較例品共優れた電波吸収特性を
有していた（比較例品の方が劣るが双方共２０dB以上の
反射減衰量であった）。従って本発明品は、最下限吸収
周波数（吸収体の厚さが５０mmであるので３GHz）付近
の低周波帯においても良好な電波吸収特性を示し、比較
例品に比べて広帯域に優れた電波吸収特性を有する電波
吸収体であることが明らかとなった。Although not shown in the drawing, in the frequency band of 4.4 GHz or more, the product of this example and the product of the comparative example had excellent electromagnetic wave absorption characteristics (the product of the comparative example is inferior, but both have a value of 20 dB or more. It was return loss). Therefore, the product of the present invention exhibits excellent electromagnetic wave absorption characteristics even in the low frequency band near the lowest absorption frequency (3 GHz because the thickness of the absorber is 50 mm), and has an excellent electromagnetic wave absorption in a wider band than the comparative example product. It became clear that it is a radio wave absorber having characteristics.
［効果］ 以上説明した本発明の電波吸収体によれば、極性ポリマ
ーからなる人工繊維から構成されているので、各繊維自
体の太さが一定で、各種太さの繊維も容易に得られ、均
一な品質の繊維を使用することができると共にカーボン
も付着し易く、厚さの一様なカーボン被膜を形成するこ
とが容易であるので、優れた電波吸収性を有する電波吸
収体が実現される。[Effect] According to the radio wave absorber of the present invention described above, since the artificial fiber made of a polar polymer is used, the thickness of each fiber itself is constant, and fibers of various thicknesses can be easily obtained. Since it is possible to use fibers of uniform quality, carbon easily adheres, and it is easy to form a carbon coating with a uniform thickness, so that an electromagnetic wave absorber having excellent electromagnetic wave absorption is realized. .
また本発明の電波吸収体は、繊維密度を厚さ方向に変化
させており、密度が粗の面を電波入射方向に向けて使用
すれば、吸収すべき電波が吸収体の電波入射面において
反射される度合が緩和されるため、より良好な電波吸収
特性を達成することが可能となる。Further, in the radio wave absorber of the present invention, the fiber density is changed in the thickness direction, and if the surface with a rough density is used with the radio wave incident direction facing, the radio wave to be absorbed is reflected at the radio wave incident surface of the absorber. Since the degree to be performed is relaxed, it is possible to achieve better radio wave absorption characteristics.
さらに、繊維同士は結合されているので簡単にほぐれて
しまうことはなく、本電波吸収体の敷設時等に少々手荒
に扱っても損傷することがない等、本発明は優れた効果
を奏する。Further, since the fibers are bonded to each other, they are not easily disentangled, and the present invention has excellent effects such as not being damaged even if it is handled a little rough when the radio wave absorber is laid.
第１図は本発明の電波吸収体の一実施例の外観を示す斜
視図、第２図は電波吸収特性を測定するための測定系を
示す模式図、第３図は第２図の測定系により測定した電
波吸収体の電波吸収特性を示す特性図である。 Ｆ…繊維、１…結合部、２，２′…ホーンアンテナ、３
…検波器、４…金属板、５…供試電波吸収体、Ｔ…送
信、Ｒ…受信FIG. 1 is a perspective view showing the appearance of an embodiment of a radio wave absorber of the present invention, FIG. 2 is a schematic diagram showing a measurement system for measuring radio wave absorption characteristics, and FIG. 3 is a measurement system of FIG. It is a characteristic view which shows the electromagnetic wave absorption characteristic of the electromagnetic wave absorber measured by. F ... Fiber, 1 ... Coupling part, 2, 2 '... Horn antenna, 3
… Detector, 4… Metal plate, 5… Sample electromagnetic wave absorber, T… Transmit, R… Receive
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大内 裕 和歌山県有田市箕島663番地 三菱電線工 業株式会社箕島製作所内 (72)発明者 川中 輝明 和歌山県有田市箕島663番地 三菱電線工 業株式会社箕島製作所内 (72)発明者 中村 豊 和歌山県有田市箕島663番地 三菱電線工 業株式会社箕島製作所内 審査官 市川 裕司 (56)参考文献 特開 昭60−136300（ＪＰ，Ａ) 特開 昭63−141397（ＪＰ，Ａ) 特公 昭33−10633（ＪＰ，Ｂ１) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ouchi 663 Minoshima, Arita-shi, Wakayama Mitsubishi Cable Industries, Ltd.Minoshima Works (72) Teruaki Kawanaka 663 Minoshima, Arita, Wakayama Mitsubishi Electric Industrial Co., Ltd. Minoshima Works (72) Inventor Yutaka Nakamura 663 Minoshima, Arita-shi, Wakayama Yuji Ichikawa, Examiner, Mitsushima Works, Mitsubishi Cable Industries, Ltd. (56) Reference JP-A-60-136300 (JP, A) JP-A 63-141397 (JP, A) JP-B 33-10633 (JP, B1)
Claims (1)
ポリマーからなる繊維を、各種繊維が少なくとも５重量
％含有されるように互いに絡ませると共に互いに結合さ
せて形成されたマット状繊維集合体からなる電波吸収体
であって、該繊維集合体は、その厚さ方向に繊維密度を
変化させていることを特徴とする電波吸収体。1. A mat-like fiber aggregate formed by entwining and bonding fibers made of polar polymers of various thicknesses coated with carbon so that each fiber contains at least 5% by weight. A radio wave absorber comprising a body, wherein the fiber assembly has a fiber density varied in a thickness direction thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63245235A JPH0632417B2 (en) | 1988-09-29 | 1988-09-29 | Radio wave absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63245235A JPH0632417B2 (en) | 1988-09-29 | 1988-09-29 | Radio wave absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0291997A JPH0291997A (en) | 1990-03-30 |
| JPH0632417B2 true JPH0632417B2 (en) | 1994-04-27 |
Family
ID=17130667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63245235A Expired - Lifetime JPH0632417B2 (en) | 1988-09-29 | 1988-09-29 | Radio wave absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0632417B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006314016A (en) * | 2005-05-09 | 2006-11-16 | Mitsubishi Cable Ind Ltd | Radio wave absorbing structural body |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003059031A1 (en) * | 2001-12-28 | 2003-07-17 | Mitsubishi Cable Industries, Ltd. | Radio wave absorber |
| JP4122364B2 (en) * | 2006-08-23 | 2008-07-23 | 三菱電線工業株式会社 | Radio wave absorber and manufacturing method thereof |
| JP5452706B2 (en) * | 2010-02-23 | 2014-03-26 | 東急建設株式会社 | Reinforced concrete partition |
| JP2015146351A (en) * | 2014-01-31 | 2015-08-13 | 王子ホールディングス株式会社 | Electromagnetic wave absorber |
| JP6438687B2 (en) * | 2014-06-17 | 2018-12-19 | 三菱電線工業株式会社 | Radio wave absorber and manufacturing method thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60136300A (en) * | 1983-12-24 | 1985-07-19 | 阿部俊三 | Radio wave absorber |
| JPS63141397A (en) * | 1986-12-04 | 1988-06-13 | 株式会社フジタ | Film structure for electric wave absorption |
-
1988
- 1988-09-29 JP JP63245235A patent/JPH0632417B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006314016A (en) * | 2005-05-09 | 2006-11-16 | Mitsubishi Cable Ind Ltd | Radio wave absorbing structural body |
| WO2006121029A1 (en) * | 2005-05-09 | 2006-11-16 | Mitsubishi Cable Industries, Ltd. | Electromagnetic wave absorption structure body and antenna cover |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0291997A (en) | 1990-03-30 |
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