JPH0128517B2 - - Google Patents
Info
- Publication number
- JPH0128517B2 JPH0128517B2 JP7090482A JP7090482A JPH0128517B2 JP H0128517 B2 JPH0128517 B2 JP H0128517B2 JP 7090482 A JP7090482 A JP 7090482A JP 7090482 A JP7090482 A JP 7090482A JP H0128517 B2 JPH0128517 B2 JP H0128517B2
- Authority
- JP
- Japan
- Prior art keywords
- radio wave
- weight
- ferrite
- layer
- wave absorber
- 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
Links
- 239000006096 absorbing agent Substances 0.000 claims description 20
- 229910000859 α-Fe Inorganic materials 0.000 claims description 13
- 239000000835 fiber Substances 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 230000002745 absorbent Effects 0.000 claims description 9
- 239000002250 absorbent Substances 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- 239000005011 phenolic resin Substances 0.000 claims description 7
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 5
- 229920001568 phenolic resin Polymers 0.000 claims description 5
- 238000010030 laminating Methods 0.000 claims 1
- 239000010410 layer Substances 0.000 description 20
- 238000010521 absorption reaction Methods 0.000 description 11
- 239000000203 mixture Substances 0.000 description 5
- 239000002356 single layer Substances 0.000 description 3
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Aerials With Secondary Devices (AREA)
Description
【発明の詳細な説明】
本発明は、コンクリート、鉄骨等の建造物等に
よる電波障害を除去するための電波吸収体に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radio wave absorber for removing radio wave interference caused by buildings such as concrete and steel frames.
近年、テレビ、レーダー等の発達普及に伴い、
建造物、鉄橋、船舶、飛行機等に起因する電波の
不要反射、妨害反射が問題になつている。この反
射を防止するためにこれらの構造物に電波吸収体
を設けることが必要となつている。 In recent years, with the development and spread of television, radar, etc.
Unnecessary reflections and interference reflections of radio waves caused by buildings, iron bridges, ships, airplanes, etc. have become a problem. In order to prevent this reflection, it is necessary to provide radio wave absorbers in these structures.
この電波吸収体として種々の組成物が開発され
ており、例えばフエライト焼結体、フエライト層
とカーボンブラツク層の複合体、フエライトとカ
ーボンブラツクの混合体、更にこれに高分子合成
樹脂を加えたもの等がある。これらの電波吸収体
は各々すぐれた電波吸収特性をもつているが、電
波吸収特性を与える周波数帯域を広くするために
は、吸収体の厚みが極端に厚くなつたり、また薄
形の吸収体では充分な周波数帯域がとれないと云
う欠点があつた。例えば、第１図は磁気損失を利
用する複合フエライトの電波吸収特性であるが、
反射係数0.1（反射減衰量として20dBに相当する）
以下の周波数帯域が極めて狭いために実用上種々
の困難を伴う。 Various compositions have been developed as radio wave absorbers, including sintered ferrite, composites of ferrite and carbon black layers, mixtures of ferrite and carbon black, and compositions in which polymeric synthetic resins are added. etc. Each of these radio wave absorbers has excellent radio wave absorption characteristics, but in order to widen the frequency band that provides radio wave absorption characteristics, the thickness of the absorber must be extremely thick, or the thickness of the absorber must be extremely thin. The drawback was that a sufficient frequency band could not be obtained. For example, Figure 1 shows the radio wave absorption characteristics of composite ferrite that utilizes magnetic loss.
Reflection coefficient 0.1 (equivalent to 20dB return loss)
Since the following frequency bands are extremely narrow, various practical difficulties arise.
本発明はかゝるマイクロ波領域で、広い周波数
帯域で反射係数が低く、従つて電波吸収特性の良
いしかも薄い電波吸収体を提供するものである。 The present invention provides a thin radio wave absorber that has a low reflection coefficient over a wide frequency band in the microwave region, and therefore has good radio wave absorption characteristics.
第２図は従来のフエライト電波吸収体を単層で
用いた場合の断面構造であり、導電性の構造物１
の上に電波吸収体２が貼付けてある。そして電波
Ａが、A′で示す如く反射する状態に於て、１及
び２の表面で反射する成分の和が殆ど０となるよ
うに２の組成や厚さを調整することにより、構造
物外に電波障害を起さぬようにするものである。
これに対し本発明は第３図に示す如く、吸収層３
と変成層４を２層に積層して構造物に貼付け、吸
収層３の入力インピーダンスを変成層４で空気中
のインピーダンスと整合をとるように構成したも
のであり、整合状態に於ては、A′で示す各成分
の和は殆ど０となつて電磁波の反射を抑制してい
る。 Figure 2 shows the cross-sectional structure when a conventional ferrite radio wave absorber is used in a single layer, and shows the conductive structure 1.
A radio wave absorber 2 is pasted on top of the . Then, in the state where radio wave A is reflected as shown by A', by adjusting the composition and thickness of 2 so that the sum of the components reflected on the surfaces of 1 and 2 becomes almost 0, it is possible to This is to prevent radio wave interference from occurring.
On the other hand, in the present invention, as shown in FIG.
The metamorphic layer 4 is laminated in two layers and attached to a structure, and the input impedance of the absorption layer 3 is matched with the impedance in the air in the metamorphic layer 4. In the matched state, The sum of each component indicated by A' is almost 0, suppressing the reflection of electromagnetic waves.
本発明のもう１つの特徴は上記２層中の吸収層
３に２〜70重量％のスチールフアイバーが分散さ
れていることである。スチールフアイバーが２重
量％以下では本発明の目的であるマイクロ波領域
の広い周波数帯での良好な吸収特性を示さない。
30％以上では強度が著しく低下し大面積の吸収体
を製造することが困難である。吸収層の基体はフ
エライト10〜80重量％、フエノール樹脂５〜80重
量％が吸収層全体の重量に対して適当な量であ
る。フエノール５重量％以下では成形性が可撓性
に問題があり最低５重量％以上のフエノールを必
要とする。またフエライト10重量％以下では電波
吸収特性が充分でない。フエノール樹脂若しくは
フエライトが80重量％を超えると成形性が困難と
なる。 Another feature of the present invention is that 2 to 70% by weight of steel fibers are dispersed in the absorbent layer 3 of the two layers. If the steel fiber content is less than 2% by weight, it will not exhibit good absorption characteristics in a wide frequency band of the microwave region, which is the object of the present invention.
If it exceeds 30%, the strength will drop significantly and it will be difficult to manufacture a large-area absorber. The base material of the absorbent layer contains 10 to 80% by weight of ferrite and 5 to 80% by weight of phenolic resin in appropriate amounts based on the weight of the entire absorbent layer. If the amount of phenol is less than 5% by weight, there will be problems in moldability and flexibility, so a minimum amount of phenol of 5% by weight or more is required. Further, if the ferrite is less than 10% by weight, the radio wave absorption properties are not sufficient. If the phenolic resin or ferrite exceeds 80% by weight, moldability becomes difficult.
又スチールフアイバーは直径10〜100μで、長
さ１〜５mmのものが種々検討した結果均一な組成
物を製作する上で好結果が得られた。 Further, as a result of various studies of steel fibers having a diameter of 10 to 100 μm and a length of 1 to 5 mm, good results were obtained in producing a uniform composition.
次に上記吸収層３の上面に積層する変成層は、
フエノール樹脂40〜100重量％、フエライト０〜
60重量％からなり、フアイバーは含まない。上記
吸収層３、変成層４は別々に製作して後で接着し
ても、同時に一体成型しても構わない。 Next, the metamorphic layer laminated on the upper surface of the absorption layer 3 is:
Phenol resin 40~100% by weight, ferrite 0~
It consists of 60% by weight and does not contain fibers. The absorbent layer 3 and the metamorphic layer 4 may be manufactured separately and bonded together later, or they may be integrally molded at the same time.
発明に用いるスチールフアイバーとしては、例
えば本発明者らが開発した特願昭56―170395号及
び特願昭56―170397号で出願した金属フアイバー
製造法による、均一な長さを有し、毛玉になりに
くいスチールフアイバーがこの場合好適である。 For example, the steel fiber used in the invention is manufactured by the metal fiber manufacturing method developed by the present inventors in Japanese Patent Application No. 56-170395 and Japanese Patent Application No. 56-170397. Steel fibers are preferred in this case because they are less susceptible to corrosion.
第４図は、本発明の電波吸収体の特性の１例を
示すもので、広い周波帯域で電波吸収特性が優れ
ていることが第１図の従来例と比較すれば一目遼
然である。 FIG. 4 shows an example of the characteristics of the radio wave absorber of the present invention, and it is immediately clear that the radio wave absorber has excellent radio wave absorption characteristics over a wide frequency band when compared with the conventional example shown in FIG.
次に実施例によつて説明する。 Next, an example will be explained.
実施例
フエライト粉末67.9重量％、フエノール樹脂粉
末29.1重量％、平均直径60μ、長さ1.0mmでイメー
ジアナライザーによる長さの偏差測定値が0.6mm
であるスチールフアイバー（0.1％Ｃ）を3.0重量
％を均一に混合し、温度160℃、圧力10Kg／cm2で
300mm×300mm×1.2mmの形状にプレス成型して吸
収層となるべき板を作製した。これとは別にフエ
ライト10重量％、フエノール樹脂90重量％からな
る変成層となるべき板を吸収層板と同一寸法に製
作したものを用意し、吸収層と変成層を接着材に
て接着し、4.7mm厚で300×300の寸法の電波吸収
体を作製した。Example Ferrite powder 67.9% by weight, phenolic resin powder 29.1% by weight, average diameter 60μ, length 1.0mm, length deviation measured by image analyzer is 0.6mm
3.0% by weight of steel fiber (0.1%C) was mixed uniformly, and the temperature was 160℃ and the pressure was 10Kg/ cm2.
A plate to be used as an absorbent layer was prepared by press molding into a shape of 300 mm x 300 mm x 1.2 mm. Separately, prepare a plate that is to become a metamorphic layer consisting of 10% by weight of ferrite and 90% by weight of phenol resin, manufactured to the same dimensions as the absorbent layer, and bond the absorbent layer and metamorphic layer with an adhesive. A radio wave absorber with a thickness of 4.7 mm and dimensions of 300 x 300 was fabricated.
これで8GHz〜13GHzでの反射減衰量を測定し
たところ、第４図に示す如く、従来の単層の電波
吸収体に較べて、極めて広い範囲で良好な吸収特
性を示した。 When the return loss was measured at 8 GHz to 13 GHz, as shown in FIG. 4, it showed better absorption characteristics over a much wider range than conventional single-layer radio wave absorbers.
第１図は従来の電波吸収体の吸収特性図、第２
図は従来の単層電波吸収体の使用例断面図、第３
図は本発明の使用例、第４図は本発明電波吸収体
の特性を示す図である。
１…構造物、２…電波吸収体、３…電波吸収
層、４…変成層、Ａ，A′…電波。
Figure 1 is an absorption characteristic diagram of a conventional radio wave absorber, Figure 2
The figure is a cross-sectional view of an example of the use of a conventional single-layer radio wave absorber.
The figure shows an example of the use of the present invention, and FIG. 4 is a diagram showing the characteristics of the radio wave absorber of the present invention. 1... Structure, 2... Radio wave absorber, 3... Radio wave absorbing layer, 4... Metamorphic layer, A, A'... Radio wave.
Claims (1)
〜80重量％及びスチールフアイバー２〜70重量％
からなる吸収層とフエノール樹脂40〜100重量％、
フエライト０〜60重量％からなる変成層の２層が
積層されてなることを特徴とする電波吸収体。 ２ 吸収層中の該スチールフアイバーが直径10〜
100μ、長さ１〜５mmである特許請求の範囲第１
項記載の電波吸収体。[Claims] 1. 10 to 80% by weight of ferrite, phenolic resin 5
~80% by weight and steel fiber 2~70% by weight
Absorbent layer consisting of phenolic resin 40-100% by weight,
A radio wave absorber characterized by being formed by laminating two metamorphic layers consisting of 0 to 60% by weight of ferrite. 2 The steel fiber in the absorbent layer has a diameter of 10~
100μ, length 1-5mm Claim 1
Radio wave absorber described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7090482A JPS58188189A (en) | 1982-04-27 | 1982-04-27 | Radio wave absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7090482A JPS58188189A (en) | 1982-04-27 | 1982-04-27 | Radio wave absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58188189A JPS58188189A (en) | 1983-11-02 |
| JPH0128517B2 true JPH0128517B2 (en) | 1989-06-02 |
Family
ID=13444976
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7090482A Granted JPS58188189A (en) | 1982-04-27 | 1982-04-27 | Radio wave absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58188189A (en) |
-
1982
- 1982-04-27 JP JP7090482A patent/JPS58188189A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58188189A (en) | 1983-11-02 |
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