JP3038436B1 - Dielectric wave absorber - Google Patents
Dielectric wave absorberInfo
- Publication number
- JP3038436B1 JP3038436B1 JP11104501A JP10450199A JP3038436B1 JP 3038436 B1 JP3038436 B1 JP 3038436B1 JP 11104501 A JP11104501 A JP 11104501A JP 10450199 A JP10450199 A JP 10450199A JP 3038436 B1 JP3038436 B1 JP 3038436B1
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- ghz
- wave absorber
- dielectric
- radio wave
- resin
- Prior art date
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Abstract
【要約】
【課題】１８〜１００ＧHｚで周波数にかかわらずΓが
６ｄB以上である電波吸収体を提供する。
【解決手段】導電体層と誘電体層を持つ電波吸収体であ
って、前記誘電体層の厚さは５ｍｍ以下であり、周波数
18GHz、50GHz、75GHz、100GHzにおける反射減衰量
（Γ）がいずれも６ｄB以上である電波吸収体。The present invention provides a radio wave absorber in which Γ is 6 dB or more at 18 to 100 GHz regardless of frequency. A radio wave absorber having a conductor layer and a dielectric layer, wherein the thickness of the dielectric layer is 5 mm or less,
A radio wave absorber whose return loss (Γ) at 18 GHz, 50 GHz, 75 GHz, and 100 GHz is 6 dB or more.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は電磁波吸収材料に関
するものであり、特に準ミリ波からミリ波帯域の電磁波
を広帯域に吸収する材料に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave absorbing material, and more particularly to a material that absorbs electromagnetic waves in a quasi-millimeter wave band to a millimeter wave band in a wide band.
【０００２】[0002]
【従来の技術及びその課題】携帯電話・パソコンなど最
新の情報・通信機器とそのシステムを日常一般のものと
し、無線ＬＡＮやＩＴＳなどの通信インフラ整備も進行
中である。それら市場は今後も大いに成長が期待され
る。2. Description of the Related Art The latest information and communication equipment such as mobile phones and personal computers and their systems are commonly used, and the development of communication infrastructures such as wireless LANs and ITSs is in progress. These markets are expected to grow significantly in the future.
【０００３】上記通信システムにはこれまで一般にはあ
まり使用されていなかった電波帯域準マイクロ波・準ミ
リ波帯域が割り当てられる。例えば室内高速無線LANに
は１９GHzが、ITSには６９GHzが使用される。ＥＭＣ対
策もまたこれら準ミリ波・ミリ波の帯域で行なねばなら
ない。[0003] The above communication system is assigned a radio band quasi-microwave / quasi-millimeter wave band which has not been generally used so far. For example, 19 GHz is used for indoor high-speed wireless LAN, and 69 GHz is used for ITS. EMC measures must also be taken in these quasi-millimeter and millimeter wave bands.
【０００４】従来この領域の電波吸収材料としては、フ
ェライトやカーボンの粉末と樹脂との複合体をシート状
または塗料にしたものが知られている。同電波吸収体は
いわゆる狭帯域型であって、その厚さに特有の整合周波
数付近の狭帯域のみで大きな吸収がおきる。すなわち厚
みが設定値からずれると、整合周波数も目的とする帯域
からずれが生じ、その吸収性能が悪くなるという問題点
があった。Heretofore, as a radio wave absorbing material in this region, a material in which a composite of a ferrite or carbon powder and a resin is formed into a sheet or paint is known. The radio wave absorber is a so-called narrow band type, and large absorption occurs only in a narrow band near a matching frequency specific to its thickness. That is, if the thickness deviates from the set value, the matching frequency also deviates from the target band, and there is a problem that the absorption performance deteriorates.
【０００５】一方、チタン酸バリウム（ＢａＴｉＯ3）
などの誘電損失材は、その特性がフェライトなどの磁性
損失材に比較して優れている点がないので、実用的材料
としては意味がないものとされていた（新ＯＨＭ文庫
「電波吸収体」内藤喜之著、５７頁、１９８７年）。On the other hand, barium titanate (BaTiO 3 )
Dielectric loss materials such as are not considered to be meaningful as practical materials because their properties are not superior to magnetic loss materials such as ferrite (new OHM Bunko "radio wave absorber"). Yoshiyuki Naito, p. 57, 1987).
【０００６】[0006]
【課題を解決するための手段】本発明者は、周波数18GH
z〜100GHzの準ミリ波及びミリ波領域での電波吸収材に
ついて検討を重ねた結果、図１〜６に示されるように周
波数18GHz未満の領域（例えば10GHz、15GHz）では、周
波数によって反射減衰量（Γ）が６ｄＢ以上となる誘電
率ε'と誘電損ε”の領域が大きく変化するが（図１、
２）、周波数18GHz〜100GHz（例えば18GHz、50GHz、75G
Hz、100GHz）では周波数に関わらず反射減衰量（Γ）が
６ｄＢ以上である誘電率ε'と誘電損ε”の領域はほぼ
一定であることを見出し、本発明を完成した。The inventor of the present invention has a frequency of 18GH.
As a result of repeated investigations on radio wave absorbing materials in the quasi-millimeter wave and millimeter wave regions from z to 100 GHz, as shown in FIGS. 1 to 6, in regions below a frequency of 18 GHz (for example, 10 GHz and 15 GHz), the return loss depends on the frequency. The region of the dielectric constant ε ′ and the dielectric loss ε ″ where (Γ) is 6 dB or more greatly changes (FIG. 1,
2), frequency 18GHz to 100GHz (for example, 18GHz, 50GHz, 75G
Hz and 100 GHz), the inventors have found that the region of the dielectric constant ε ′ and the dielectric loss ε ″ where the return loss (Γ) is 6 dB or more is almost constant regardless of the frequency, and completed the present invention.
【０００７】すなわち、本発明は下記の項１〜項６に関
する。 項１． 導電体層と誘電体層を持つ電波吸収体であっ
て、前記誘電体層の厚さは５ｍｍ以下であり、周波数18
GHz、50GHz、75GHz、100GHzにおける反射減衰量（Γ）
がいずれも６ｄB以上である電波吸収体。 項２． 導電体層と誘電体層を持つ電波吸収体であっ
て、前記誘電体層の厚さは５ｍｍ以下であり、周波数18
GHz〜100GHzの範囲における反射減衰量（Γ）が常に６
ｄB以上である電波吸収体。 項３． 前記誘電体層の誘電率ε'と誘電損ε”が下記
条件をみたす請求項１又は２に記載の電波吸収体： ０＜ε'≦８．３ かつ０．１＜ε”≦５．３ 項４． 誘電体層が酸化物誘電体と樹脂よりなる樹脂複
合物誘電体である項１〜３のいずれかに記載の電波吸収
体。 項５． 誘電率ε'と誘電損ε”が１８ＧＨｚ〜１００
ＧＨｚでそれぞれ一定値をとる酸化物誘電体粉末を一種
類もしくは複数種類使用することを特徴とする項４に記
載の電波吸収体。 項６． 誘電体層の厚みが３〜５ｍｍである項１〜５の
いずれかに記載の電波吸収体。That is, the present invention relates to the following items 1 to 6. Item 1. A radio wave absorber having a conductor layer and a dielectric layer, wherein the thickness of the dielectric layer is 5 mm or less, and the frequency is 18
Return loss at GHz, 50GHz, 75GHz, 100GHz (Γ)
Are all 6 dB or more radio wave absorbers. Item 2. A radio wave absorber having a conductor layer and a dielectric layer, wherein the thickness of the dielectric layer is 5 mm or less, and the frequency is 18
Return loss (Γ) in the range of GHz to 100 GHz is always 6
A radio wave absorber that is at least dB. Item 3. The electromagnetic wave absorber according to claim 1 or 2, wherein the dielectric constant ε ′ and the dielectric loss ε ″ of the dielectric layer satisfy the following conditions: 0 <ε ′ ≦ 8.3 and 0.1 <ε ″ ≦ 5.3. Item 4. Item 4. The radio wave absorber according to any one of Items 1 to 3, wherein the dielectric layer is a resin composite dielectric comprising an oxide dielectric and a resin. Item 5. Dielectric constant ε ′ and dielectric loss ε ″ are 18 GHz to 100
Item 5. The electromagnetic wave absorber according to item 4, wherein one or more kinds of oxide dielectric powders each having a constant value at GHz are used. Item 6. Item 6. The radio wave absorber according to any one of Items 1 to 5, wherein the thickness of the dielectric layer is 3 to 5 mm.
【０００８】[0008]
【発明の実施の形態】以下に本発明の内容を説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described below.
【０００９】本発明の電波吸収体で用いられる誘電体層
は、周波数18GHz〜100GHzにおける反射減衰量（Γ）が
いずれも６ｄB以上となるように、前記誘電体層の誘電
率ε’と誘電損ε”を設計する。[0009] The dielectric layer used in the radio wave absorber of the present invention has a dielectric constant ε 'and a dielectric loss such that the return loss (Γ) at a frequency of 18 GHz to 100 GHz is 6 dB or more. ε ″ is designed.
【００１０】反射減衰量Γ（ｄB）は、下記式で与えら
れる。The return loss Γ (dB) is given by the following equation.
【００１１】[0011]
【化１】 Embedded image
【００１２】反射減衰量は大きいほど、厚さは薄いほど
優れた吸収体といえるが、本発明では、現実的な要求仕
様としてΓは６ｄB以上、ｄは５ｍｍ（図１〜６）又は
３ｍｍ（図７〜１０）とし、それを満たすε’、ε”の
組み合わせを広範囲の周波数について算出し解析した。
その結果、１８〜１００ＧHｚにおいては周波数にかか
わらず、上記仕様をみたす（ε’、ε”）の範囲を見出
すに至った。この（ε’、ε”）の範囲は、ｄは５ｍｍ
のとき図１〜図４の範囲の共通部分として表すことがで
きる。The larger the return loss and the thinner the thickness, the better the absorber. However, in the present invention, 要求 is at least 6 dB and d is 5 mm (FIGS. 1 to 6) or 3 mm ( 7 to 10), combinations of ε ′ and ε ″ that satisfy the conditions were calculated and analyzed for a wide range of frequencies.
As a result, in the range of 18 to 100 GHz, regardless of the frequency, a range of (ε ′, ε ″) that satisfies the above specifications was found. In the range of (ε ′, ε ″), d was 5 mm.
In this case, it can be represented as a common part in the range of FIGS.
【００１３】図１〜図４は、ｄ＝５ｍｍ、μ’＝１、
μ”＝０、反射減衰量Γ≧６ｄB、周波数（１／λ）＝1
8GHz、50GHz、75GHzまたは100GHzを満たす（ε’、
ε”）の範囲を示す。1 to 4 show d = 5 mm, μ ′ = 1,
μ ”= 0, return loss Γ ≧ 6 dB, frequency (1 / λ) = 1
Meets 8GHz, 50GHz, 75GHz or 100GHz (ε ',
ε ″).
【００１４】同様に、図７〜図１０は、ｄ＝５ｍｍ、
μ’＝１、μ”＝０、反射減衰量Γ≧６ｄB、周波数
（１／λ）＝18GHz、50GHz、75GHzまたは100GHzを満た
す（ε’、ε”）の範囲を示す。Similarly, FIGS. 7 to 10 show that d = 5 mm,
μ ′ = 1, μ ″ = 0, return loss Γ ≧ 6 dB, frequency (1 / λ) = 18 GHz, 50 GHz, 75 GHz or 100 GHz (ε ′, ε ″).
【００１５】誘電体層の厚みが３〜５ｍｍである項６の
電波吸収体は、図１〜図４及び図７〜図１０の共通範囲
である。The electromagnetic wave absorber of item 6 in which the thickness of the dielectric layer is 3 to 5 mm is a common range of FIGS. 1 to 4 and FIGS.
【００１６】誘電体層の厚さは５ｍｍ以下、好ましくは
３ｍｍ以下であり、例えば２〜５ｍｍ、特に３〜５ｍｍ
が例示される。The thickness of the dielectric layer is 5 mm or less, preferably 3 mm or less, for example, 2 to 5 mm, particularly 3 to 5 mm.
Is exemplified.
【００１７】導電体層は、電波吸収体に通常用いられて
いる導電体を制限なく使用でき、例えばニッケル等の金
属が例示される。導電体層は、例えば誘電体層にメッキ
を行うことにより形成できる。As the conductor layer, a conductor generally used for a radio wave absorber can be used without limitation, and examples thereof include metals such as nickel. The conductor layer can be formed, for example, by plating the dielectric layer.
【００１８】周波数18GHz〜100GHzにおける誘電体層の
誘電率ε'と誘電損ε”は、好ましくは、０＜ε'≦８．
３ かつ ０．１＜ε”≦５．３；より好ましくは、３
＜ε'≦８ かつ０．５＜ε"≦５；特に好ましくは、３
＜ε'≦８ かつ０．７＜ε”≦４．２である。The dielectric constant ε ′ and the dielectric loss ε ″ of the dielectric layer at a frequency of 18 GHz to 100 GHz are preferably 0 <ε ′ ≦ 8.
3 and 0.1 <ε ″ ≦ 5.3; more preferably 3
<Ε ′ ≦ 8 and 0.5 <ε ″ ≦ 5; particularly preferably 3
<Ε ′ ≦ 8 and 0.7 <ε ″ ≦ 4.2.
【００１９】誘電体層としては、酸化物誘電体（繊維、
粉末等）と樹脂よりなる樹脂複合物誘電体が好ましく例
示される。As the dielectric layer, an oxide dielectric (fiber,
And a resin composite dielectric comprising a resin and the like.
【００２０】本発明においては、酸化物誘電体の誘電率
ε’と誘電損ε”が１８ＧＨｚ〜１００ＧＨｚでそれぞ
れ一定値をとるときに、Γが６ｄB以上である酸化物誘
電体を一種類もしくは複数種類使用することを特徴とす
る。このような酸化物誘電体としては、チタン酸バリウ
ム、チタン酸アルミン酸カリウム、チタン酸カリウム、
チタン酸ストロンチウムバリウム、チタン酸カルシウ
ム、モノクリニックチタン酸などが挙げられ、好ましく
はチタン酸バリウム、チタン酸アルミン酸カリウム、チ
タン酸カリウムが挙げられる。酸化物誘電体の商品名と
しては、ＢＴＷ（チタン酸バリウム）、ＴＡＫ（チタン
酸アルミン酸カリウム）、ＴＩＳＭＯ（チタン酸カリウ
ム）、ＢＳＴＷ（チタン酸ストロンチウムバリウム）、
ＣＴＷ（チタン酸カルシウム繊維）、ＭＴＷ（モノクリ
ニックチタン酸）（以上大塚化学株式会社製）が挙げら
れる。In the present invention, when the dielectric constant ε ′ and the dielectric loss ε ″ of the oxide dielectric take a constant value in the range of 18 GHz to 100 GHz, one or a plurality of oxide dielectrics having ６ of 6 dB or more are used. Such oxide dielectrics include barium titanate, potassium aluminate, potassium titanate,
Examples include barium strontium titanate, calcium titanate, and monoclinic titanate, and preferably barium titanate, potassium aluminate titanate, and potassium titanate. The trade names of oxide dielectrics include BTW (barium titanate), TAK (potassium aluminate titanate), TISMO (potassium titanate), BSTW (strontium barium titanate),
CTW (calcium titanate fiber) and MTW (monoclinic titanic acid) (all manufactured by Otsuka Chemical Co., Ltd.).
【００２１】誘電体層に配合される樹脂としては、熱可
塑性樹脂、熱硬化性樹脂が挙げられる。熱可塑性樹脂と
しては、ポリフェニレンエーテル（ポリフェニレンオキ
サイドを含む）、変性ポリフェニレンエーテル、ポリフ
ェニレンエーテルとポリエーテルイミドのアロイ等のポ
リフェニレンエーテル系樹脂、ポリスチレン樹脂（特に
シンジオタクチックなものが好ましい）、５−メチルペ
ンテン樹脂、環状ポリオレフィン系樹脂、耐熱性ＡＢＳ
樹脂、ポリアミド−4,6、ポリアミド−６Ｔ、ポリアミ
ド−６Ｔ、ポリアミド−６／６Ｔ等の耐熱性ポリアミド
樹脂、ポリフェニレンサルファイド樹脂、芳香族ポリサ
ルホン系樹脂、ポリエーテルイミド樹脂、ポリエーテル
ケトン樹脂、ポリエーテルニトリル樹脂、サーモトロピ
ック液晶ポリエステル樹脂、耐溶融性フッ素樹脂、熱可
塑性ポリイミド樹脂等を例示でき、好ましくはポリフェ
ニレンエーテル系樹脂、シンジオタクチックポリスチレ
ン、５−メチルペンテン樹脂、環状ポリオレフィン系樹
脂、ポリフェニレンサルファイド樹脂、ポリエーテルイ
ミド樹脂、ポリエーテルケトン樹脂、サーモトロピック
液晶ポリエステル樹脂、耐溶融性フッ素樹脂、熱可塑性
ポリイミド樹脂等を例示できる。熱硬化性樹脂として
は、トリアジン系樹脂、熱硬化性ポリフェニレンエーテ
ル系樹脂、エポキシ樹脂等を例示できる。Examples of the resin to be mixed in the dielectric layer include a thermoplastic resin and a thermosetting resin. Examples of the thermoplastic resin include polyphenylene ether (including polyphenylene oxide), modified polyphenylene ether, polyphenylene ether-based resin such as alloy of polyphenylene ether and polyetherimide, polystyrene resin (particularly preferably syndiotactic), 5-methyl Penten resin, cyclic polyolefin resin, heat resistant ABS
Resin, heat-resistant polyamide resin such as polyamide-4,6, polyamide-6T, polyamide-6T, polyamide-6 / 6T, polyphenylene sulfide resin, aromatic polysulfone resin, polyetherimide resin, polyetherketone resin, polyether Examples thereof include a nitrile resin, a thermotropic liquid crystal polyester resin, a melt-resistant fluororesin, a thermoplastic polyimide resin, and the like. , A polyether imide resin, a polyether ketone resin, a thermotropic liquid crystal polyester resin, a melt-resistant fluororesin, a thermoplastic polyimide resin and the like. Examples of the thermosetting resin include a triazine-based resin, a thermosetting polyphenylene ether-based resin, and an epoxy resin.
【００２２】該樹脂は、熱可塑性樹脂及び熱硬化性樹脂
からなる群から選ばれる少なくとも１種、好ましくは熱
可塑性樹脂の少なくとも１種を使用できる。As the resin, at least one kind selected from the group consisting of a thermoplastic resin and a thermosetting resin, preferably at least one kind of a thermoplastic resin can be used.
【００２３】酸化物誘電体と樹脂の配合比は、酸化物誘
電体：樹脂＝１〜７０重量％：９９〜３０重量％、好ま
しくは酸化物誘電体：樹脂＝３〜６０重量％：９７〜４
０重量％である。The compounding ratio of the oxide dielectric and the resin is as follows: oxide dielectric: resin = 1-70% by weight: 99-30% by weight, preferably oxide dielectric: resin = 3-60% by weight: 97- 4
0% by weight.
【００２４】[0024]
【発明の効果】本発明の電波吸収体はいわゆる広帯域型
であり、１８ＧＨｚ〜１００ＧＨｚでは６ｄＢ一定以上
の電波吸収性能をもつ。また厚みムラによる特性劣化も
わずかである。The radio wave absorber of the present invention is a so-called broadband type, and has a radio wave absorption performance of 6 dB or more at 18 GHz to 100 GHz. Also, the characteristic deterioration due to the uneven thickness is slight.
【００２５】[0025]
【実施例】以下、本発明を実施例に基づきより詳細に説
明する。 実施例１ チタン酸アルミン酸カリウム（商品名「ＴＡＫ」、大塚
化学株式会社製）を１７重量％、ＰＰ（ポリプロピレ
ン）樹脂を８３重量％配合して混練し、射出成形して厚
さ５ｍｍの誘電体層に対応する成形体（縦２０ｍｍ×横
２０ｍｍ）を作製した。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments. Example 1 17% by weight of potassium aluminate titanate (trade name "TAK", manufactured by Otsuka Chemical Co., Ltd.) and 83% by weight of PP (polypropylene) resin were blended, kneaded, and injection-molded to obtain a dielectric material having a thickness of 5 mm. A molded body (20 mm long × 20 mm wide) corresponding to the body layer was produced.
【００２６】得られた厚さ５ｍｍの誘電成形体につい
て、片面にニッケルメッキにより導電体層を形成し、誘
電体層及び導電体層を有する電波吸収体を得た。With respect to the obtained dielectric molded body having a thickness of 5 mm, a conductor layer was formed on one surface by nickel plating to obtain a radio wave absorber having the dielectric layer and the conductor layer.
【００２７】得られた電波吸収体の比誘電率は、ε＝６
−２．５ｊ（ε’＝６、ε”＝２．５）であった。The relative permittivity of the obtained radio wave absorber is ε = 6
−2.5j (ε ′ = 6, ε ″ = 2.5).
【００２８】該電波吸収体に対し、１８ＧＨｚ〜１００
ＧＨｚの電波を当てたところ、反射減衰量は常に６ｄＢ
以上であることを確認した。For the radio wave absorber, 18 GHz to 100
When a radio wave of GHz is applied, the return loss is always 6 dB.
It was confirmed that it was above.
【図１】電波吸収体の厚み５ｍｍ、周波数１００ＧＨ、
反射減衰量Γ＝６ｄＢのときのε’とε”の関係を示す
グラフである。FIG. 1 shows a thickness of a radio wave absorber of 5 mm, a frequency of 100 GH,
11 is a graph showing the relationship between ε ′ and ε ″ when the return loss Γ = 6 dB.
【図２】電波吸収体の厚み５ｍｍ、周波数７５ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 2 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 5 mm, the frequency is 75 GH, and the return loss Γ = 6 dB.
【図３】電波吸収体の厚み５ｍｍ、周波数５０ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 3 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 5 mm, the frequency is 50 GH, and the return loss Γ = 6 dB.
【図４】電波吸収体の厚み５ｍｍ、周波数１８ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 4 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 5 mm, the frequency is 18 GH, and the return loss Γ = 6 dB.
【図５】電波吸収体の厚み５ｍｍ、周波数１５ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 5 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 5 mm, the frequency is 15 GH, and the return loss Γ = 6 dB.
【図６】電波吸収体の厚み５ｍｍ、周波数１０ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 6 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 5 mm, the frequency is 10 GH, and the return loss Γ = 6 dB.
【図７】電波吸収体の厚み３ｍｍ、周波数１００ＧＨ、
反射減衰量Γ＝６ｄＢのときのε’とε”の関係を示す
グラフである。FIG. 7 shows a thickness of a radio wave absorber of 3 mm, a frequency of 100 GH,
11 is a graph showing the relationship between ε ′ and ε ″ when the return loss Γ = 6 dB.
【図８】電波吸収体の厚み３ｍｍ、周波数７５ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 8 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 3 mm, the frequency is 75 GH, and the return loss Γ = 6 dB.
【図９】電波吸収体の厚み３ｍｍ、周波数５０ＧＨ、反
射減衰量Γ＝６ｄＢのときのε’とε”の関係を示すグ
ラフである。FIG. 9 is a graph showing the relationship between ε ′ and ε ″ when the thickness of the radio wave absorber is 3 mm, the frequency is 50 GH, and the return loss Γ = 6 dB.
【図１０】電波吸収体の厚み３ｍｍ、周波数１８ＧＨ、
反射減衰量Γ＝６ｄＢのときのε’とε”の関係を示す
グラフである。FIG. 10 shows a thickness of a radio wave absorber of 3 mm, a frequency of 18 GH,
11 is a graph showing the relationship between ε ′ and ε ″ when the return loss Γ = 6 dB.
Claims (6)
って、前記誘電体層の厚さは５ｍｍ以下であり、周波数
18GHz、50GHz、75GHz、100GHzにおける反射減衰量
（Γ）がいずれも６ｄB以上である電波吸収体。1. A radio wave absorber having a conductor layer and a dielectric layer, wherein the thickness of said dielectric layer is 5 mm or less,
A radio wave absorber whose return loss (Γ) at 18 GHz, 50 GHz, 75 GHz, and 100 GHz is 6 dB or more.
って、前記誘電体層の厚さは５ｍｍ以下であり、周波数
18GHz〜100GHzの範囲における反射減衰量（Γ）が常に
６ｄB以上である電波吸収体。2. A radio wave absorber having a conductor layer and a dielectric layer, wherein the thickness of said dielectric layer is 5 mm or less,
A radio wave absorber whose return loss (Γ) in the range of 18 GHz to 100 GHz is always 6 dB or more.
下記条件をみたす請求項１又は２に記載の電波吸収体： ０＜ε'≦８．３かつ０．３＜ε”≦５．３3. The electromagnetic wave absorber according to claim 1, wherein the dielectric constant ε ′ and the dielectric loss ε ″ of the dielectric layer satisfy the following condition: 0 <ε ′ ≦ 8.3 and 0.3 <ε. "≦ 5.3
脂複合物誘電体である請求項１〜３のいずれかに記載の
電波吸収体。4. The radio wave absorber according to claim 1, wherein the dielectric layer is a resin composite dielectric comprising an oxide dielectric and a resin.
００ＧＨｚでそれぞれ一定値をとる酸化物誘電体粉末を
一種類もしくは複数種類使用することを特徴とする請求
項４に記載の電波吸収体。5. A dielectric constant ε ′ and a dielectric loss ε ″ of 18 GHz to 1
5. The radio wave absorber according to claim 4, wherein one or a plurality of oxide dielectric powders each having a constant value at 00 GHz are used.
１〜５のいずれかに記載の電波吸収体。6. The radio wave absorber according to claim 1, wherein the thickness of the dielectric layer is 3 to 5 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11104501A JP3038436B1 (en) | 1999-04-12 | 1999-04-12 | Dielectric wave absorber |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11104501A JP3038436B1 (en) | 1999-04-12 | 1999-04-12 | Dielectric wave absorber |
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| Publication Number | Publication Date |
|---|---|
| JP3038436B1 true JP3038436B1 (en) | 2000-05-08 |
| JP2000299587A JP2000299587A (en) | 2000-10-24 |
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|---|---|---|---|
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010080911A (en) * | 2008-04-30 | 2010-04-08 | Tayca Corp | Wide band electromagnetic wave absorbing material and method of manufacturing same |
| JP2010210297A (en) * | 2009-03-09 | 2010-09-24 | Furukawa Electric Co Ltd:The | Wide coverage radar apparatus |
| JPWO2015093600A1 (en) * | 2013-12-20 | 2017-03-23 | 株式会社クラレ | Electromagnetic wave absorber and method for producing the same |
| JP7308312B2 (en) * | 2018-03-12 | 2023-07-13 | マクセル株式会社 | real-time transceiver |
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