JPH0468800B2 - - Google Patents
Info
- Publication number
- JPH0468800B2 JPH0468800B2 JP57191936A JP19193682A JPH0468800B2 JP H0468800 B2 JPH0468800 B2 JP H0468800B2 JP 57191936 A JP57191936 A JP 57191936A JP 19193682 A JP19193682 A JP 19193682A JP H0468800 B2 JPH0468800 B2 JP H0468800B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- radio wave
- wave absorber
- ferrite
- powder
- 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.)
- Expired - Lifetime
Links
- 239000006096 absorbing agent Substances 0.000 claims description 52
- 229910000859 α-Fe Inorganic materials 0.000 claims description 27
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 19
- 229910052751 metal Inorganic materials 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 17
- 239000000843 powder Substances 0.000 claims description 16
- 239000003822 epoxy resin Substances 0.000 claims description 10
- 229920000647 polyepoxide Polymers 0.000 claims description 10
- 229910018605 Ni—Zn Inorganic materials 0.000 claims description 7
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000000835 fiber Substances 0.000 claims description 4
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 4
- 229920002803 thermoplastic polyurethane Polymers 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 63
- 239000002356 single layer Substances 0.000 description 11
- 239000000696 magnetic material Substances 0.000 description 7
- 239000002245 particle Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 239000003989 dielectric material Substances 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- 230000002745 absorbent Effects 0.000 description 3
- 239000002250 absorbent Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- OWYWGLHRNBIFJP-UHFFFAOYSA-N Ipazine Chemical compound CCN(CC)C1=NC(Cl)=NC(NC(C)C)=N1 OWYWGLHRNBIFJP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000004567 concrete Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000005060 rubber Substances 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- OMZSGWSJDCOLKM-UHFFFAOYSA-N copper(II) sulfide Chemical compound [S-2].[Cu+2] OMZSGWSJDCOLKM-UHFFFAOYSA-N 0.000 description 1
- -1 etc. Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 229910000702 sendust Inorganic materials 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
Landscapes
- Aerials With Secondary Devices (AREA)
- Laminated Bodies (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Description
【発明の詳細な説明】
（技術分野）
この発明は電波吸収体に関し、更に詳細には、
広帯域特性が得られるとともに薄型化が可能な２
層型電波吸収体に関する。[Detailed Description of the Invention] (Technical Field) This invention relates to a radio wave absorber, and more specifically,
Achieves broadband characteristics and can be made thinner 2
Regarding layered radio wave absorbers.
（背景技術）
従来から船舶、航空機あるいは鉄塔のような電
波反射体の反射電流を抑制するために、このよう
な反射体上に磁性体や抵抗体等の電波吸収体を装
着する場合が多い。(Background Art) Conventionally, in order to suppress the reflected current of a radio wave reflector such as a ship, an aircraft, or a steel tower, a radio wave absorber such as a magnetic material or a resistor is often mounted on such a reflector.
従来の単層型電波吸収体の例を第１図に示す。
この電波吸収体は、例えばフエライト等の磁性材
料もしくはカーボン等の誘電体を樹脂中に混合分
散させて形成された吸収層１に金属板２を接着し
て構成されている。この種の単層型電波吸収体は
薄く構成することができ、例えばＸバンド（８〜
12GHz）では厚さを２mm以下にすることも可能で
ある。また、単層であることから製造上の管理点
が少なく、施工性も優れているという利点があ
る。しかしながら、この種の単層型電波吸収体は
第４図に示すように、20dB以上の減衰量が得ら
れる帯域が中心周波数に対して10％程度と狭いこ
とが欠点であつた。 An example of a conventional single-layer radio wave absorber is shown in FIG.
This radio wave absorber is constructed by adhering a metal plate 2 to an absorbing layer 1 formed by mixing and dispersing a magnetic material such as ferrite or a dielectric material such as carbon in a resin. This type of single-layer radio wave absorber can be constructed thinly, for example, in the X band (8 to 8
(12 GHz), it is possible to reduce the thickness to 2 mm or less. In addition, since it is a single layer, there are fewer points to control during manufacturing, and it has the advantage of excellent workability. However, as shown in FIG. 4, this type of single-layer radio wave absorber has a drawback in that the band in which attenuation of 20 dB or more can be obtained is as narrow as about 10% of the center frequency.
これに対して、広帯域化を計るために第２図に
示すような２層型電波吸収体が提案されている。
この電波吸収体は、フエライトと金属短繊維を樹
脂に混合分散して成る第１層１１の一面にフエラ
イトを樹脂に混合分散して成る第２層１２が図示
の如く積層され、第１層１１の第２層１２が積層
された面と相対向する面に金属板１３が裏打ちさ
れて構成されている。この２層型電波吸収体にお
いて、電磁波的には第１層１１は吸収層として作
用し、第２層１２はマツチングトランスとして作
用する。このフエライトを用いた従来の２層型電
波吸収体は、前述の単層型のものに比べて広帯域
化を計ることができる反面、厚さが大になるとい
う欠点があつた。 In response to this, a two-layer radio wave absorber as shown in FIG. 2 has been proposed in order to widen the band.
In this radio wave absorber, a second layer 12 made of ferrite mixed and dispersed in resin is laminated on one surface of a first layer 11 made of ferrite and short metal fibers mixed and dispersed in resin, as shown in the figure. The surface opposite to the surface on which the second layer 12 is laminated is lined with a metal plate 13. In this two-layer radio wave absorber, in terms of electromagnetic waves, the first layer 11 acts as an absorption layer, and the second layer 12 acts as a matching transformer. Although the conventional two-layer radio wave absorber using this ferrite can achieve a wider band than the single-layer type described above, it has the disadvantage of being thicker.
（発明の課題）
この発明は上述の問題点を解決するために成さ
れたものであつて、広帯域特性が得られるととも
に薄型化が可能な電波吸収体を提供することを目
的とするものである。(Problems to be solved by the invention) This invention was made to solve the above-mentioned problems, and its purpose is to provide a radio wave absorber that can obtain broadband characteristics and can be made thinner. .
（発明の構成及び作用）
第３図は、この発明による電波吸収体の一実施
例を示す断面図である。同図に示す如く、この電
波吸収体は、吸収層として作用する第１の吸収基
体層２１とマツチングトランスとして作用する第
２層２２と金属層２３とから構成される、いわゆ
る２層型電波吸収体である。各層は接着剤による
接着等の方法で積層される。第１層２１は、軟磁
性金属粉もしくは軟磁性金属粉及びフエライト粉
と導電性物質とを第１のマトリツクス中に混合分
散させて形成される。一方、第２層２２は、誘電
性物質と磁性材料とを第２のマトリツクス中に混
合分散して形成される。(Structure and operation of the invention) FIG. 3 is a sectional view showing an embodiment of the radio wave absorber according to the invention. As shown in the figure, this radio wave absorber is a so-called two-layer radio wave absorber composed of a first absorbing base layer 21 that acts as an absorption layer, a second layer 22 that acts as a matching transformer, and a metal layer 23. It is an absorber. Each layer is laminated by a method such as bonding with an adhesive. The first layer 21 is formed by mixing and dispersing soft magnetic metal powder or soft magnetic metal powder and ferrite powder and a conductive substance in a first matrix. On the other hand, the second layer 22 is formed by mixing and dispersing a dielectric material and a magnetic material in a second matrix.
第１層２１に使用される軟磁性金属粉として、
軟鉄、硅素鋼、カーボニル鉄、センダスト鉄、パ
ーマロイ等の軟磁性体の粉末が挙げられる。また
導電性物質としては粉末、繊維等の形状を有する
金属、炭素等の物質を使用することができ、硫化
銅等の導電体をコーテイングした合成繊維を用い
ても良い。繊維状導電体の使用は、電波吸収体に
強度、耐候性が要求される場合には特に好適であ
る。第１のマトリツクス（粉末を混合するための
母材）としては各種樹脂、ゴム、コンクリート、
セラミツク等を使用することができる。 As the soft magnetic metal powder used for the first layer 21,
Examples include powders of soft magnetic materials such as soft iron, silicon steel, carbonyl iron, sendust iron, and permalloy. Further, as the conductive substance, a substance such as metal or carbon in the form of powder or fiber can be used, and synthetic fiber coated with a conductor such as copper sulfide may also be used. The use of a fibrous conductor is particularly suitable when the radio wave absorber is required to have strength and weather resistance. The first matrix (base material for mixing powder) can be various resins, rubber, concrete,
Ceramic or the like can be used.
この発明の第１層２１に分散混合される磁性
体、すなわち軟磁性金属粉もしくは軟磁性金属粉
及びフエライト粉の体積混合比は10〜65％である
のが好ましく、導電性物質の体積混合比は１〜30
％であるのが好ましく、これら両者の体積混合比
の和は65％以下であるのが好ましい。 The volume mixing ratio of the magnetic material, i.e., soft magnetic metal powder or soft magnetic metal powder and ferrite powder dispersed and mixed in the first layer 21 of the present invention is preferably 10 to 65%, and the volume mixing ratio of the conductive material is preferably 10 to 65%. is 1-30
%, and the sum of the volumetric mixing ratios of both is preferably 65% or less.
一方、第２層２２に分散混合される磁性体とは
鉄粉、フエライト粉等であり、誘電体とはTiO2
等である。また第２のマトリツクスとしては、各
種樹脂、ゴム、コンクリート、セラミツク等を使
用することができる。第１及び第２のマトリツク
スは同種のものを使用してもよく、また異種のも
のであつてもよい。 On the other hand, the magnetic material dispersed and mixed in the second layer 22 is iron powder, ferrite powder, etc., and the dielectric material is TiO 2
etc. Furthermore, various resins, rubber, concrete, ceramics, etc. can be used as the second matrix. The first and second matrices may be of the same type or may be of different types.
金属層２３にはアルミニウム、鉄、ステンレス
等の種々の金属を用いることができる。 Various metals such as aluminum, iron, and stainless steel can be used for the metal layer 23.
次にこの発明の好ましい実施例を従来例と比較
しながら説明する。 Next, a preferred embodiment of the present invention will be described in comparison with a conventional example.
第４図は、Mn−Znフエライト10体積％、カー
ボニル鉄15体積％、エポキシ樹脂75体積％から成
る吸収基体層を有する単層型電波吸収体の反射量
と周波数の関係を示す図である。同図からわかる
ように、反射減衰量20dB以上の周波数帯域巾Δ
と該周波数帯域の中心周波数0との比（比帯域）
は10％程度となつている。 FIG. 4 is a diagram showing the relationship between the amount of reflection and the frequency of a single-layer radio wave absorber having an absorbing base layer consisting of 10% by volume of Mn--Zn ferrite, 15% by volume of carbonyl iron, and 75% by volume of epoxy resin. As can be seen from the figure, the frequency band width Δ with return loss of 20 dB or more
and the center frequency 0 of the frequency band (fractional band)
is around 10%.
第５図は、この発明による第１実施例の２層型
電波吸収体の反射量と周波数の関係を示す図であ
る。この実施例の電波吸収体の第１層は、カーボ
ニル鉄（粒径１〜5μｍ）22体積％、炭素短繊維
（直径15〜25μｍ、長さ200〜400μｍ）８体積％を
エポキシ樹脂（チバガイギー社製：GY250−
HY850）70体積％に混合分散した厚さ0.95mmの層
である。第２層は、Ni−Znフエライト（粒径0.5
〜10μｍ）５体積％、酸化チタン（粒径0.1〜2μ
ｍ）３体積％をエポキシ樹脂（チバガイギー社
製：GY250−HY850）92体積％に混合分散した
厚さ3.65mmの層である。従つて、吸収基体層全体
の厚さは4.6mmである。また金属層として厚さ２
mmのアルミニウム板を用いた。 FIG. 5 is a diagram showing the relationship between the amount of reflection and frequency of the two-layer radio wave absorber of the first embodiment of the present invention. The first layer of the radio wave absorber in this example was made of 22% by volume of carbonyl iron (particle size: 1-5 μm), 8% by volume of short carbon fibers (diameter: 15-25 μm, length: 200-400 μm), and epoxy resin (Ciba Geigy Co., Ltd.). Manufactured by: GY250−
HY850) is a 0.95mm thick layer mixed and dispersed at 70% by volume. The second layer is Ni-Zn ferrite (particle size 0.5
~10μm) 5% by volume, titanium oxide (particle size 0.1~2μm)
m) A layer with a thickness of 3.65 mm in which 3% by volume was mixed and dispersed in 92% by volume of epoxy resin (GY250-HY850 manufactured by Ciba Geigy). Therefore, the total thickness of the absorbent substrate layer is 4.6 mm. Also, the metal layer has a thickness of 2
An aluminum plate of mm was used.
第６図は、この発明による第２実施例の２層型
電波吸収体の反射量と周波数の関係を示す図であ
る。この実施例の電波吸収体の第１層は、カーボ
ニル鉄（粒径１〜5μｍ）10体積％、Ni−Znフエ
ライト（粒径0.5〜10μｍ）15体積％、炭素短繊維
（直径15〜25μｍ、長さ200〜400μｍ）９体積％を
エポキシ樹脂（チバガイギー社製：GY250−
HY850）66体積％に混合分散した厚さ1.0mmの層
である。第２の吸収基体層は、酸化チタン（粒径
0.1〜2μｍ）３体積％、Ni−Znフエライト９体積
％をウレタン樹脂（日本ポリウレタン社製：
FAN−12コルネートHL）88体積％に混合分散し
た厚さ3.7mmの層である。従つて、吸収基体層全
体の厚さは4.7mmである。また、金属層として厚
さ２mmのアルニウム板を用いた。 FIG. 6 is a diagram showing the relationship between the amount of reflection and frequency of a two-layer radio wave absorber according to a second embodiment of the present invention. The first layer of the radio wave absorber in this example consists of carbonyl iron (particle size 1 to 5 μm) 10% by volume, Ni-Zn ferrite (particle size 0.5 to 10 μm) 15% by volume, short carbon fibers (diameter 15 to 25 μm), Length 200 to 400 μm) 9% by volume of epoxy resin (manufactured by Ciba Geigy: GY250−
HY850) is a 1.0mm thick layer mixed and dispersed at 66% by volume. The second absorbent substrate layer is made of titanium oxide (particle size
0.1~2μm) 3% by volume and 9% by volume of Ni-Zn ferrite in urethane resin (manufactured by Nippon Polyurethane Co., Ltd.:
FAN-12 Cornate HL) is a 3.7 mm thick layer mixed and dispersed at 88% by volume. Therefore, the total thickness of the absorbent substrate layer is 4.7 mm. Furthermore, an aluminum plate with a thickness of 2 mm was used as the metal layer.
第５図及び第６図から明らかなように、この発
明による第１及び第２実施例の電波吸収体の反射
減衰量20dB以上の比帯域（Δ／0）は約50％と
第４図の従来の単層型電波吸収体に比べて著しく
改善されることがわかる。 As is clear from FIGS. 5 and 6, the specific bandwidth (Δ/ 0 ) of the return loss of 20 dB or more of the radio wave absorbers of the first and second embodiments of the present invention is about 50%, which is about 50%. It can be seen that this is significantly improved compared to the conventional single-layer radio wave absorber.
一方、第７図に第１層にフエライトを用いた従
来の２層型電波吸収体と第１層に鉄粉、鉄粉及び
フエライトを用いたこの発明の２層型電波吸収体
の反射減衰量が20dB以上の比帯域（Δ／0）と
厚さとの関係を示す。なお、これらは第２層（表
層）にエポキシ樹脂のみを用いた例であり、第２
層に誘電体、磁性体を含ませた場合には更に厚さ
を薄くすることができる。同図に示す如く、第１
層に鉄粉もしくは鉄粉及びフエライトを用いたこ
の発明の実施例の２層型電波吸収体は、第１層に
フエライトを用いた第２図に示すような従来の２
層型電波吸収体に比べて、同じ比帯域（反射減衰
量が20dB以上）を得るのにその厚さをかなり薄
くすることができる。さらに、同じ厚さであつて
もこの発明の実施例の電波吸収体は、従来のフエ
ライトを用いた２層型電波吸収体に比べて比帯域
を広くすることが可能となる。 On the other hand, FIG. 7 shows the return loss of the conventional two-layer radio wave absorber using ferrite in the first layer and the two-layer radio wave absorber of the present invention using iron powder, iron powder, and ferrite in the first layer. shows the relationship between the fractional bandwidth (Δ/ 0 ) of 20 dB or more and the thickness. Note that these are examples in which only epoxy resin is used for the second layer (surface layer);
When the layer contains a dielectric material or a magnetic material, the thickness can be further reduced. As shown in the figure, the first
The two-layer radio wave absorber of the embodiment of the present invention using iron powder or iron powder and ferrite in the layer is different from the conventional two-layer radio wave absorber as shown in FIG. 2 in which the first layer is made of ferrite.
Compared to layered radio wave absorbers, the thickness can be made considerably thinner to obtain the same specific bandwidth (return loss of 20 dB or more). Furthermore, even if the thickness is the same, the radio wave absorber according to the embodiment of the present invention can have a wider specific band than a conventional two-layer radio wave absorber using ferrite.
この発明による電波吸収体が、従来のフエライ
トを用いた２層型電波吸収体と比較して広帯域で
ある理由を第８図を用いて説明する。第８図は、
第１層がNi−Znフエライト40体積％をエポキシ
樹脂に分散混合させて形成されている従来例の２
層型電波吸収体（曲線Ｂ）、及び第１層がカーボ
ニル鉄40体積％をエポキシ樹脂に分散混合させて
形成されているこの発明による２層型電波吸収体
（曲線Ａ）の比透磁率μ′，μ″と周波数との関係を
示すグラフである。ここで複素透磁率はμ・＝μ″−
jμ″であらわされ、μ′は実数部、μ″は虚数部、ｊ
は√−１を示す。第８図から明らかなように、こ
の発明による電波吸収体の比透磁率μ′，μ″は従来
例に比べて周波数による変化が小さく、かなり大
きな値を有しており、特に周波数の高い領域にお
いてその傾向が顕著である。このため、この発明
による２層型電波吸収体の比帯域は、フエライト
を用いた従来の２層型電波吸収体より大きくなつ
ている。 The reason why the radio wave absorber according to the present invention has a wider band than the conventional two-layer radio wave absorber using ferrite will be explained with reference to FIG. Figure 8 shows
Conventional example 2 in which the first layer is formed by dispersing and mixing 40% by volume of Ni-Zn ferrite in epoxy resin.
Relative magnetic permeability μ of a layered radio wave absorber (curve B) and a two-layer radio wave absorber (curve A) according to the present invention in which the first layer is formed by dispersing and mixing 40 volume % of carbonyl iron in an epoxy resin. This is a graph showing the relationship between ′, μ″ and frequency. Here, the complex magnetic permeability is μ・=μ″−
jμ″, μ′ is the real part, μ″ is the imaginary part, j
indicates √−1. As is clear from FIG. 8, the relative magnetic permeability μ', μ'' of the radio wave absorber according to the present invention has a smaller change with frequency than the conventional example, and has a considerably large value, especially in the high frequency region. For this reason, the specific band of the two-layer radio wave absorber according to the present invention is larger than that of the conventional two-layer radio wave absorber using ferrite.
（発明の効果）
以上説明したように、この発明によれば、次に
示す効果がある。(Effects of the Invention) As explained above, the present invention has the following effects.
(1) 単層構造のものに比べて、20dB以上の反射
減衰量が得られる帯域巾を３倍以上にすること
ができる。(1) Compared to a single-layer structure, the bandwidth at which return loss of 20 dB or more can be obtained can be more than tripled.
(2) 同じ２層構造の場合でも、フエライトのみを
用いたものより広帯域にすることができる。(2) Even with the same two-layer structure, the band can be made wider than that using only ferrite.
(3) 同じ帯域巾（20dB以上の反射減衰量）を得
るのにフエライトのみを用いたものより薄型化
することができる。(3) It can be made thinner than one using only ferrite to obtain the same bandwidth (return loss of 20 dB or more).
第１図は従来の単層型電波吸収体を示す断面
図、第２図は第１層にフエライトを用いた２層型
電波吸収体を示す断面図、第３図はこの発明によ
る２層型電波吸収体の一実施例を示す断面図、第
４図は第１図の単層型電波吸収体の反射量と周波
数の関係を示すグラフ、第５図は第１層に鉄粉を
用いたこの発明の電波吸収体の第１実施例の反射
量と周波数の関係を示すグラフ、第６図は第１層
に鉄粉及びフエライトを用いたこの発明の電波吸
収体の第２実施例の反射量と周波数の関係を示す
グラフ、第７図は第２図に示す従来の電波吸収体
とこの発明による電波吸収体の20dB以上の反射
減衰量が得られる比帯域（Δ／0）と周波数の
関係を示すグラフ、第８図はフエライトを用いた
従来の２層型電波吸収体とこの発明による電波吸
収体の比透磁率と周波数の関係を示すグラフであ
る。
２１……第１層、２２……第２層、２３……金
属層。
Fig. 1 is a cross-sectional view showing a conventional single-layer radio wave absorber, Fig. 2 is a cross-sectional view showing a two-layer radio wave absorber using ferrite in the first layer, and Fig. 3 is a two-layer radio wave absorber according to the present invention. A cross-sectional view showing an example of a radio wave absorber, Fig. 4 is a graph showing the relationship between the amount of reflection and frequency of the single-layer radio wave absorber shown in Fig. 1, and Fig. 5 is a graph showing the relationship between the amount of reflection and frequency of the single-layer radio wave absorber shown in Fig. 1. A graph showing the relationship between the amount of reflection and the frequency of the first embodiment of the radio wave absorber of this invention, and FIG. 6 shows the reflection of the second embodiment of the radio wave absorber of this invention using iron powder and ferrite in the first layer. Figure 7 is a graph showing the relationship between quantity and frequency, and shows the ratio of frequency and fractional band (Δ/ 0 ) at which a return loss of 20 dB or more can be obtained for the conventional radio wave absorber shown in Figure 2 and the radio wave absorber according to the present invention. FIG. 8 is a graph showing the relationship between relative magnetic permeability and frequency of a conventional two-layer radio wave absorber using ferrite and a radio wave absorber according to the present invention. 21...first layer, 22...second layer, 23...metal layer.
Claims (1)
樹脂中に混合分散して成る第１層と、酸化チタン
粉末とNi−Znフエライト粉末とをエポキシ樹脂
中に混合分散して成り前記第１層の一面に設けら
れる第２層と、前記第１層の一面であつて前記第
２層が設けられた面と相対向する面に設けられる
金属板層とから構成されることを特徴とする電波
吸収体。 ２ カーボニル鉄粉末及びNi−Znフエライト粉
末と導電性繊維とをエポキシ樹脂中に混合分散し
て成る第１層と、酸化チタン粉末とNi−Znフエ
ライト粉末とをウレタン樹脂中に混合分散して成
り前記第１層の一面に設けられる第２層と、前記
第１層の一面であつて前記第２層が設けられた面
と相対向する面に設けられる金属板層とから構成
されることを特徴とする電波吸収体。[Claims] 1. A first layer consisting of carbonyl iron powder and conductive fiber mixed and dispersed in epoxy resin, and a first layer consisting of titanium oxide powder and Ni-Zn ferrite powder mixed and dispersed in epoxy resin. A second layer provided on one surface of the first layer, and a metal plate layer provided on one surface of the first layer opposite to the surface on which the second layer is provided. Characteristic radio wave absorber. 2 The first layer is made by mixing and dispersing carbonyl iron powder, Ni-Zn ferrite powder, and conductive fiber in epoxy resin, and the first layer is made by mixing and dispersing titanium oxide powder and Ni-Zn ferrite powder in urethane resin. A second layer provided on one surface of the first layer, and a metal plate layer provided on one surface of the first layer opposite to the surface on which the second layer is provided. Characteristic radio wave absorber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57191936A JPS5982799A (en) | 1982-11-02 | 1982-11-02 | Radio wave absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57191936A JPS5982799A (en) | 1982-11-02 | 1982-11-02 | Radio wave absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5982799A JPS5982799A (en) | 1984-05-12 |
| JPH0468800B2 true JPH0468800B2 (en) | 1992-11-04 |
Family
ID=16282913
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57191936A Granted JPS5982799A (en) | 1982-11-02 | 1982-11-02 | Radio wave absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5982799A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0310600U (en) * | 1989-06-15 | 1991-01-31 | ||
| JP3401650B2 (en) * | 1994-01-20 | 2003-04-28 | エヌイーシートーキン株式会社 | Electromagnetic interference suppressor |
| JPH1075088A (en) * | 1996-08-30 | 1998-03-17 | Tokin Corp | Manufacture of electromagnetic interference suppression sheet |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS504423A (en) * | 1973-05-18 | 1975-01-17 | ||
| JPS5620720A (en) * | 1979-07-25 | 1981-02-26 | Hino Motors Ltd | Supercharger for internal combustion engine |
-
1982
- 1982-11-02 JP JP57191936A patent/JPS5982799A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS504423A (en) * | 1973-05-18 | 1975-01-17 | ||
| JPS5620720A (en) * | 1979-07-25 | 1981-02-26 | Hino Motors Ltd | Supercharger for internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5982799A (en) | 1984-05-12 |
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