JP4832223B2

JP4832223B2 - Radio wave absorber

Info

Publication number: JP4832223B2
Application number: JP2006239440A
Authority: JP
Inventors: 一美加藤; 勇一遠藤; 斉西田
Original assignee: Nikko Co Ltd; Tokin EMC Engineering Co Ltd; NEC Tokin Corp
Current assignee: Nikko Co Ltd; Tokin Corp; Tokin EMC Engineering Co Ltd
Priority date: 2006-09-04
Filing date: 2006-09-04
Publication date: 2011-12-07
Anticipated expiration: 2026-09-04
Also published as: JP2008066340A

Description

本発明は電波吸収体に関し、更に詳しくは電波無響室（電波暗室）用の電波吸収体に関し、特に単体及び複合にすることによりさまざまな電波周波数に対応することが可能な電波吸収体に関する。 The present invention relates to a radio wave absorber, and more particularly to a radio wave absorber for an anechoic chamber (a anechoic chamber), and more particularly to a radio wave absorber that can cope with various radio wave frequencies by using a single body and a composite body.

電波を利用した通信情報技術・機器がその利便性ゆえに急速に発展、普及している。そして、機器並びにその周辺では電波障害が発生している。
一般に、電子機器の製造メーカでは、自社が製造している製品が、電磁妨害波が入射しても誤動作等の障害をおこさないし、又、他の製品に悪影響を与える電磁波を発生しないということを保障する必要性が求められている。即ち、上記した二つの要求を満足するための電磁的両立性（ＥＭＣ）が電子製品には必要となっている。そのような電波障害に対して機器の電磁的両立性（ＥＭＣ）及び電磁干渉性（ＥＭＩ）、さらに電磁環境改善等の課題解決が求められている。これらを解決する手段として電波吸収体の需要が増加している。又、上記した電磁的両立性（ＥＭＣ）を評価するための測定用の部屋が電波無響室（電波暗室）である。 Communication information technology and equipment using radio waves are rapidly developing and spreading due to their convenience. And radio interference has occurred in the equipment and its surroundings.
In general, electronic device manufacturers indicate that their products do not cause malfunctions or other problems even when electromagnetic interference waves are incident, and do not generate electromagnetic waves that adversely affect other products. There is a need to guarantee. That is, an electronic product is required to have electromagnetic compatibility (EMC) to satisfy the above two requirements. There is a need to solve problems such as electromagnetic compatibility (EMC) and electromagnetic interference (EMI) of devices and improvement of electromagnetic environment against such radio interference. As a means for solving these problems, demand for radio wave absorbers is increasing. The measurement room for evaluating the electromagnetic compatibility (EMC) is an anechoic chamber (an anechoic chamber).

この電波無響室（電波暗室）は、調査対象としている電子機器以外からの電波の影響を受けないようにするため、部屋の外壁側には電波が侵入しないように金属板で電磁波をシールドし、内壁側には電子機器から出た電磁波が壁で反射しないように電波吸収体が貼り付けて構成されている。尚、この電波無響室（電波暗室）には、大型製品（自動車、大型電子機器等）のＥＭＣ調査を行う大型暗室と、比較的小物の電子機器のＥＭＣ調査を行うための小型暗室の２種類がある。 This anechoic chamber (an anechoic chamber) shields electromagnetic waves with a metal plate so that radio waves do not enter the outside wall of the room in order to avoid the influence of radio waves from other than the electronic equipment under investigation. On the inner wall side, a radio wave absorber is attached so that the electromagnetic wave emitted from the electronic device is not reflected by the wall. In this anechoic chamber (anechoic chamber), there are two types: a large darkroom that conducts EMC surveys of large products (cars, large electronic devices, etc.) and a small darkroom that conducts EMC surveys of relatively small electronic devices. There are types.

そして、電波吸収体には、周波数３０ＭＨｚ〜１ＧＨｚ帯域対応のフェライトタイル、周波数１ＧＨｚ〜１８ＧＨｚ帯域をカバーする電波吸収体として発泡体中に導電性材料や磁性材料を表面塗布或は練混ぜて、ピラミッド形状或は楔形状にしたものがある。 For the electromagnetic wave absorber, a ferrite tile corresponding to a frequency of 30 MHz to 1 GHz band, and an electromagnetic wave absorber covering the frequency of 1 GHz to 18 GHz band, a conductive material or a magnetic material is surface coated or kneaded in the foam, and a pyramid There are shapes or wedges.

また、周波数９００ＭＨｚ、１．５ＧＨｚ、２．４ＧＨｚ、５．２ＧＨｚ、及び５．８ＧＨｚなどの特定周波数にそれぞれ限定した合成樹脂、ゴム、或はセメント、アスファルトなどに磁性粉末材料を練混ぜたもの、或は練混ぜた合成樹脂、ゴムを発泡したものが開発、実用化されている。
さらに、これらを組み合わせて広帯域に対応する複層型電波吸収体が前記電波無響室（電波暗室）の内壁側に使用されている。 The frequency 900 MHz, 1.5 GHz, 2.4GHz, 5.2 GHz, and if Shigeki fat that limits each particular frequencies such as 5.8 GHz, rubber or cement, and kneading the magnetic powder material such as asphalt Products, or mixed synthetic resins and rubber foams have been developed and put to practical use.
Further, a multi-layer type electromagnetic wave absorber corresponding to a wide band by combining them is used on the inner wall side of the anechoic chamber (anechoic chamber).

上記した電波吸収体の製造方法としては、磁性粉末材料をプレス成形後焼成する方法（フェライトタイル）、合成樹脂やゴム等に磁性粉末材料やカーボン、カーボン繊維のような導電性材料を練混ぜ、その材料を金型でプレス成形、真空成形、或は射出成形する方法等がある。
前者の焼成品（フェライトタイル）は変形が大きく、大判のタイルを寸法精度よく成形することは困難であり、大判化には不適である。
又、後者の場合は、ニーダ（kneader：こね合わせ機）で練混ぜ材料を作るが、そのニーダや練混ぜ材料を射出成形するノズル等は、練混ぜ材料に混入されている磁性粉末材料（導電性材料）によって磨耗し易く、その結果、磨耗部品の交換や買い替え等によりコスト高になるという問題点を有する。 As a manufacturing method of the above-mentioned radio wave absorber, a method of firing a magnetic powder material after press molding (ferrite tile), a magnetic powder material, a conductive material such as carbon, carbon fiber, etc. are mixed into a synthetic resin or rubber, There are methods such as press molding, vacuum molding, or injection molding of the material using a mold.
The former fired product (ferrite tile) is greatly deformed, and it is difficult to form a large tile with high dimensional accuracy, which is unsuitable for large size.
In the latter case, a kneader (kneader) is used to make a kneaded material. The kneader or the nozzle for injection molding the kneaded material is a magnetic powder material (conductive) mixed in the kneaded material. Material), and as a result, there is a problem that the cost increases due to replacement or replacement of worn parts.

更に、前記練混ぜ材料で成形した電波吸収体が不要になり廃棄する場合、有機物である合成樹脂，ゴムと、無機物である磁性材料の分離分別が実質不可能である。また、発泡品では自由な形状にカットできる利点がある反面、沢山の端材が出て無駄が多く、コスト高になり、不経済であるなどの課題を抱えている。 Furthermore, when the radio wave absorber molded with the kneaded material is no longer needed and discarded, it is practically impossible to separate and separate the organic synthetic resin and rubber from the inorganic magnetic material. In addition, foamed products have the advantage of being able to be cut into a free shape, but there are problems such as a lot of scraps coming out and wasteful, high cost and uneconomical.

特開２０００−１８８５１３号公報JP 2000-188513 A 特開２００４−１７２２００号公報JP 2004-172200 A

本発明は上記した従来の技術が有する問題点に鑑みてなされたもので、その目的とするところは、磁性粉末材料の使用量（充填量）に制限がなく、しかも、その磁性粉末材料が成形装置等に影響せず、コストを低減し得る電波吸収体を提供することにある。
又、他の目的は、周波数に応じた電波吸収特性の調整を簡単に行うことができる電波吸収体を提供することにある。 The present invention has been made in view of the problems of the above-described conventional techniques. The object of the present invention is that there is no restriction on the amount (filling amount) of the magnetic powder material, and the magnetic powder material is molded. An object of the present invention is to provide a radio wave absorber that can reduce the cost without affecting the apparatus or the like.
Another object is to provide a radio wave absorber that can easily adjust radio wave absorption characteristics according to frequency.

上記目的を達成するために本発明が講じた技術的手段は、磁性粉末材料を他のマトリックスと練混ぜることなくそのまま容器に充填・封入して構成する。容器の大きさは、運搬、取り付け作業に支障とならない重量まで大判化が可能である。
具体的には、電波の入射方向と対向する表面部材と、その表面部材の裏側に接合する裏面部材からなり、少なくとも電波が入射する表面部材を非導電性材料で構成した容器に、磁性粉末材料をそのまま充填・封入したことを特徴とする。
前記容器は、表面部材と裏面部材とで磁性粉末材料を充填・封入し得る空間を区画形成し、表面部材の形状は、表面に円錐形状、角錐形状、楔形状等の凹凸形状が形成されている。裏面部材の形状は、表面部材と同様、表面全面が平板状、或は表面部材の凹凸形状と対応する相似形の凹凸形状として、表・裏面部材間に一定厚さ（幅）の空間が区画形成されるようにしている。
表面部材の凹凸形状は、大きさの異なる凹凸を組み合わせて配置してもよい。例えば、大きい円錐形状を格子状に配置し、その格子状に配置した円錐の底面で囲まれた平面部分の中央位置に小さい円錐形状を配置するなどが挙げられる。 The technical means taken by the present invention in order to achieve the above object is configured by filling and enclosing a magnetic powder material in a container as it is without mixing with another matrix. The size of the container can be increased to a weight that does not hinder transportation and installation.
Specifically, a magnetic powder material is provided in a container comprising a surface member facing the incident direction of the radio wave and a back member bonded to the back side of the surface member, and at least the surface member on which the radio wave is incident is made of a non-conductive material. It is characterized by being filled and sealed as it is.
Said container, a space capable of filling and encapsulating the magnetic powder material in the surface member and rear surface member is defined and formed, the shape of the surface member is conical on the surface, a pyramid shape, irregular shape, such as wedge-shaped is formed The The shape of the back member is the same as that of the front member, but the entire surface is flat, or a similar uneven shape corresponding to the uneven shape of the front member, and a space of a certain thickness (width) is defined between the front and back members. To be formed .
The uneven shape of the surface member may be arranged by combining unevenness having different sizes. For example, a large conical shape may be arranged in a lattice shape, and a small conical shape may be disposed at the center position of a plane portion surrounded by the bottom surface of the cone arranged in the lattice shape.

容器に充填・封入する磁性粉末材料としては、フェライト、カルボニル鉄、軟磁性金属、磁鉄鉱（砂鉄）、及びイルメナイト等の磁性損失を有するもので、それらのうちの一種類又は数種類を組み合わせて使用することができる。また、その磁性粉末材料の大きさとしては、前記容器の空間に充填し得る大きさであればよく、例えば前記空間の厚さ（幅）を７ｍｍとした場合、粒径０．５μｍ〜５ｍｍ位が好適である。また、使用する磁性粉末材料の大きさ（粒径）は、１種類に限らず、大小組み合わせて使用してもよい。そうすることで、磁性粉末材料相互間に生じる隙間部分に、小さい粒径の粉末を充填することで、隙間（未充填空間）の発生を防止できる。 The magnetic powder material to be filled and sealed in the container has magnetic loss such as ferrite, carbonyl iron, soft magnetic metal, magnetite (sand iron), and ilmenite, and one or several of them are used in combination. be able to. The size of the magnetic powder material may be any size that can fill the space of the container. For example, when the thickness (width) of the space is 7 mm, the particle size is about 0.5 μm to 5 mm. Is preferred. Further, the size (particle diameter) of the magnetic powder material to be used is not limited to one type, and may be used in a combination of sizes. By doing so, a gap (unfilled space) can be prevented from being generated by filling the gap portion generated between the magnetic powder materials with a powder having a small particle diameter.

又、前記容器の表面部材を構成する非導電性の材料としては、ガラス（セラミックス）、合成樹脂材（熱硬化性樹脂：エポキシ樹脂、不飽和ポリエステル樹脂、ウレタン樹脂、メラミン樹脂等、熱可塑性樹脂：ポリエチレン樹脂、ポリプロピレン樹脂、アクリル樹脂、塩化ビニル樹脂、ポリスチレン樹脂、ポリアセタール樹脂、ポリアミド樹脂、ポリカーボネート樹脂等）の一種類又は数種類の組み合わせで構成するなど任意である。また、ガラス繊維を補強材として混入してもよい。
そして、上記表面部材の厚さは、０．１〜５ｍｍの範囲が好適で、使用材料にあわせて前記の厚さを決定する。尚、表面部材の厚さが０．１ｍｍ未満の場合は磁性粉末材料の充填により表面形状が変形、或は破損するなどの問題があり、５ｍｍ以上の場合は容器の重量が重くなり、取り扱いに難点を有する。
更に裏面部材は前記非導電性材料或いは金属、カーボン材の導電性材料から形成されていても良い。
Nonconductive materials constituting the surface member of the container include glass (ceramics), synthetic resin (thermosetting resin: epoxy resin, unsaturated polyester resin, urethane resin, melamine resin, etc., thermoplastic resin. : Polyethylene resin, polypropylene resin, acrylic resin, vinyl chloride resin, polystyrene resin, polyacetal resin, polyamide resin, polycarbonate resin, etc.) and any other combination. Moreover, you may mix glass fiber as a reinforcing material.
And the thickness of the said surface member has the suitable range of 0.1-5 mm, and determines the said thickness according to a material to be used. In addition, when the thickness of the surface member is less than 0.1 mm, there is a problem that the surface shape is deformed or damaged by filling with the magnetic powder material. When the thickness is 5 mm or more, the weight of the container becomes heavy and handling is difficult. Has difficulties.
Further, the back member may be formed of the non-conductive material, or a conductive material such as metal or carbon.

又、本発明に係る電波吸収体はこれ単独で使用してもよいが、他の電波吸収体と組み合わせて使用することもできる。例えば、フェライトタイルの上面に本発明に係る電波吸収体を接合載置して使用してもよい。 The radio wave absorber according to the present invention may be used alone or in combination with other radio wave absorbers. For example, the radio wave absorber according to the present invention may be mounted on the upper surface of the ferrite tile.

上記手段によれば、非導電性の材料からなる容器に、磁性粉末材料をそのまま充填して構成するため、簡単に構成でき、しかも充填量の調整は該容器の空間部の容積によって容易に調整することができる。 According to the above means, a container made of a non-conductive material is filled with the magnetic powder material as it is, so that it can be easily configured and the filling amount is easily adjusted by the volume of the space of the container. can do.

前記容器における磁性粉末材料を充填する空間は、表面部材と裏面部材を平板形状とした場合は平板状（タイル形状）の電波吸収体を構成でき、表面部材及び裏面部材を円錐形、角錐形、楔形状等の中空凹凸形状に成形して容器とした場合は、両部材の周壁間に一定の厚さ（幅）の充填空間を区画形成でき、磁性粉末材料で一定厚さの壁厚（凹凸）を有した電波吸収体を容易に構成できる。 The space filled with the magnetic powder material in the container can constitute a flat plate (tile shape) radio wave absorber when the front member and the back member have a flat plate shape, and the front member and the back member have a conical shape, a pyramid shape, When the container is formed into a hollow concavo-convex shape such as a wedge shape, a filling space with a constant thickness (width) can be defined between the peripheral walls of both members, and the wall thickness (concave / convex) with a magnetic powder material ) Can be easily configured.

本発明の電波吸収体は、磁性粉末材料を他のマトリックスと練混ぜることなく容器に充填・封入したものであるから、電波吸収体（容器）は運搬、取付作業に支障がない重量まで大判化が可能で、しかも容易に製作することができる。
しかも、磁性粉末材料をそのまま容器に充填・封入するため、従来製品の製造に必要とされたニーダや射出成形機は不要で、且つそれらニーダや射出成形機のノズルの磨耗による部品交換等の経済的負担増に伴うコスト高がなく、経済的である。
更に、容器に磁性粉末材料を充填・封入したものであるから、電波吸収体が不要になり廃棄する場合、分別を容易に行うことができ、磁性材料及び合成樹脂材の再利用、再資源化が可能となる。 Since the electromagnetic wave absorber of the present invention is a container in which a magnetic powder material is filled and sealed without being mixed with another matrix, the electromagnetic wave absorber (container) is enlarged to a weight that does not hinder transportation and mounting operations. And can be easily manufactured.
Moreover, since the magnetic powder material is filled and sealed in the container as it is, there is no need for kneaders and injection molding machines, which are required for the manufacture of conventional products, and economics such as parts replacement due to wear of nozzles of these kneaders and injection molding machines This is economical because there is no high cost associated with an increase in the burden on the environment.
In addition, since the container is filled and sealed with magnetic powder material, when the wave absorber is no longer needed and discarded, it can be easily separated, and the magnetic material and synthetic resin material can be reused and recycled. Is possible.

又、磁性粉末材料を収容する容器の表面（電波が入射する面）に凹凸形状を付与し、その形状に沿って磁性粉末材料を充填・封入した場合は、電波吸収性能を特定周波数のみならず、広帯域の電波吸収体とすることができる。
更に、本発明にかかる電波吸収体をフェライトタイルと組み合わせて複層構造（積層）とすることで、広帯域に電波吸収性能を発揮できる電波吸収体を提供できる。それにより、電波無響室（電波暗室）に好適な電波吸収体を提供する。 In addition, when the surface of the container containing the magnetic powder material (surface on which radio waves are incident) is provided with an uneven shape, and the magnetic powder material is filled and sealed along the shape, the radio wave absorption performance is not limited to a specific frequency. A broadband electromagnetic wave absorber can be obtained.
Furthermore, the electromagnetic wave absorber which can exhibit the electromagnetic wave absorption performance in a wide band can be provided by combining the electromagnetic wave absorber concerning this invention with a ferrite tile, and setting it as a multilayer structure (lamination | stacking). Thereby, a radio wave absorber suitable for a radio anechoic chamber (a radio anechoic chamber) is provided.

以下、本発明に係る電波吸収体の実施の形態を図面に基づいて説明する。
図１は、容器を構成する表面部材及び裏面部材が凹凸形状を有した電波吸収体を示し、電波吸収体Ａは、容器Ａ１と、その容器Ａ１に充填・封入した磁性粉末材料Ａ２とで構成されている。 Embodiments of a radio wave absorber according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a radio wave absorber in which a front surface member and a back surface member constituting a container have an uneven shape, and the radio wave absorber A is composed of a container A1 and a magnetic powder material A2 filled and enclosed in the container A1. Has been.

容器Ａ１は、非導電性材料である熱硬化性樹脂（例えば、不飽和ポリエステル樹脂）で、表面（電波が入射する面）に中空の大小の円錐形２、３を膨出形成した表面部材１と、非導電性材料である熱硬化性樹脂（例えば、不飽和ポリエステル樹脂）で前記表面部材１の大円錐形２と対応する位置に、前記円錐形２の周壁内面と一定の間隔Ｌを確保する大円錐形２’を格子状に配置して膨出形成すると共に、該大円錐形２’以外の部分は平坦面３’とした裏面部材１’とで構成されている。 The container A1 is a thermosetting resin (for example, unsaturated polyester resin) which is a non-conductive material, and a surface member 1 in which hollow large and small cones 2 and 3 are bulged and formed on the surface (surface on which radio waves are incident). And a certain distance L from the inner surface of the peripheral wall of the conical shape 2 at a position corresponding to the large conical shape 2 of the surface member 1 with a thermosetting resin (for example, unsaturated polyester resin) which is a non-conductive material. The large cone 2 'is arranged in a lattice shape to form a bulge, and the portion other than the large cone 2' is composed of a back surface member 1 'having a flat surface 3'.

前記表面部材１は、平面視正方形をなし、その内部に大円錐形２が格子状に配置形成され、その大円錐形２で囲まれた平面部分の中央位置に小円錐形３が配置形成されている。図示の表面部材１は、大円錐形が２５個（５×５）、小円錐形が１６個（４×４）を示す。
同様に、裏面部材１’は、平面視正方形をなし、その内部に大円錐形２’が格子状に配置形成され、その大円錐形２’以外の部分は平坦面３’に形成されている。図示の裏面部材１’は、大円錐形２’が２５個（５×５）を示す。
そして、前記表面部材１及び裏面部材１’は、例えば厚さを１ｍｍに保って形成され、それぞれの外周には表面部材１の内側に裏面部材１’を嵌合して密閉を確立するフランジ５、５’が形成されている。 The surface member 1 has a square shape in plan view, a large cone 2 is arranged and formed in a lattice shape inside, and a small cone 3 is arranged and formed at the center position of a plane portion surrounded by the large cone 2. ing. The illustrated surface member 1 has 25 large cones (5 × 5) and 16 small cones (4 × 4).
Similarly, the back member 1 ′ has a square shape in plan view, and a large cone 2 ′ is arranged and formed in a lattice shape in the inside thereof, and a portion other than the large cone 2 ′ is formed on a flat surface 3 ′. . The illustrated back member 1 ′ has 25 large cones 2 ′ (5 × 5).
The front surface member 1 and the back surface member 1 ′ are formed, for example, with a thickness of 1 mm, and a flange 5 that establishes a hermetic seal by fitting the back surface member 1 ′ inside the surface member 1 on the outer periphery thereof. 5 'is formed.

前記容器Ａ１の空間内に充填・封入する磁性粉末材料Ａ２は、フェライト、カルボニル鉄、軟磁性金属、磁鉄鉱（砂鉄）、及びイルメナイト等の磁性損失を有するもので、その大きさ（粒径）は、前記表面部材１と裏面部材１’とで形成される充填空間の厚さ（幅）に応じて決定される。例えば、大円錐形２と大円錐形２’とで区画される空間ａの厚さ（幅）が７ｍｍとした場合、使用する磁性粉末材料の大きさは０．５μｍ〜５ｍｍの範囲が好ましい。尚、充填・封入する磁性粉末材料の材質及び、大きさ（粒径）は、求める電波吸収特性（周波数帯域）に応じて適宜選択することができる。 The magnetic powder material A2 filled and sealed in the space of the container A1 has magnetic losses such as ferrite, carbonyl iron, soft magnetic metal, magnetite (sand iron), and ilmenite, and the size (particle size) is The thickness is determined according to the thickness (width) of the filling space formed by the front surface member 1 and the back surface member 1 ′. For example, when the thickness (width) of the space a defined by the large cone 2 and the large cone 2 ′ is 7 mm, the size of the magnetic powder material to be used is preferably in the range of 0.5 μm to 5 mm. The material and size (particle size) of the magnetic powder material to be filled and sealed can be appropriately selected according to the required radio wave absorption characteristics (frequency band).

前記構成により、表面部材１の大円錐形２と裏面部材１’の大円錐形２’によって区画される一定厚さの円錐形状の空間ａと、表面部材１の小円錐形３と裏面部材１’の平坦面３’によって区画される円錐形の空間ａ’と、表面部材１の平坦面４と裏面部材１’の平坦面３’とで区画される平板状の空間ａ”に、磁性粉末材料Ａ２が充填・封入されて電波吸収体Ａが完成される。 With the above configuration, a conical space a having a constant thickness defined by the large cone 2 of the surface member 1 and the large cone 2 ′ of the back member 1 ′, the small cone 3 of the surface member 1 and the back member 1 Magnetic powder in a conical space a ′ defined by the “flat surface 3 ′” and a flat space a ″ defined by the flat surface 4 of the front surface member 1 and the flat surface 3 ′ of the back surface member 1 ′ The radio wave absorber A is completed by filling and enclosing the material A2.

図５は電波吸収体Ａを構成する容器Ａ１の他の構成を示す。
図５（ａ）は、容器Ａ１を構成する表面部材１及び裏面部材１’の表面全面を平坦面に形成したもので、表面部材１と裏面部材１’との間に一定厚さ（幅）の充填空間がけいせいされ、その充填空間に磁性粉末材料Ａ２をそのまま充填・封入することで平板状の電波吸収体が完成する。即ち、電波の入射面が平坦なタイル形状の電波吸収体を構成できる。 FIG. 5 shows another configuration of the container A1 constituting the radio wave absorber A.
FIG. 5A shows a case where the entire surface of the front surface member 1 and the back surface member 1 ′ constituting the container A1 is formed as a flat surface, and has a constant thickness (width) between the front surface member 1 and the back surface member 1 ′. The filling space is filled with and filled with the magnetic powder material A2 as it is, thereby completing a flat wave absorber. That is, it is possible to configure a tile-shaped radio wave absorber having a flat radio wave incident surface.

図５（ｂ）は、容器Ａ１を構成する表面部材１の表面に四角錐形状（ピラミッド形状）を縦横方向に連続して形成し、裏面部材１’は前記実施の形態で示した円錐形の場合と同様、表面部材１の四角錐形状の周壁内面と一定厚さ（幅）の充填空間を形成するよう四角錐形状（ピラミッド形状）を縦横方向に連続して形成する。そして、表面部材１と裏面部材１’とで区画される四角錐形の一定厚さ（幅）の充填空間に磁性粉末材料Ａ２を充填・封入することで、四角錐形の凸部が縦横方向に連続して配置形成された電波吸収体が完成すい。尚、裏面部材１’を図５（ａ）に示した裏面部材１’と同様、表面全面を平坦面に形成した場合は、表面部材１における四角錐形の空間部分が充填空間となり、四角錐形の充填空間に磁性粉末材料が充填・封入された電波吸収体を構成することができる。 In FIG. 5B, a quadrangular pyramid shape (pyramid shape) is continuously formed in the vertical and horizontal directions on the surface of the surface member 1 constituting the container A1, and the back surface member 1 ′ has the conical shape shown in the above embodiment. Similarly to the case, a quadrangular pyramid shape (pyramid shape) is continuously formed in the vertical and horizontal directions so as to form a filling space having a constant thickness (width) with the inner surface of the square pyramid-shaped peripheral wall of the surface member 1. Then, by filling and enclosing the magnetic powder material A2 in a quadrangular pyramid filling space of constant thickness (width) defined by the front surface member 1 and the back surface member 1 ′, the quadrangular pyramidal convex portions are vertically and horizontally oriented. The radio wave absorber arranged and formed continuously is completed. When the back member 1 ′ is formed as a flat surface on the entire surface as in the case of the back member 1 ′ shown in FIG. 5A, the square pyramid space portion on the surface member 1 becomes a filling space, and the quadrangular pyramid. An electromagnetic wave absorber in which a magnetic powder material is filled and enclosed in a shaped filling space can be configured.

図５（ｃ）は、容器Ａ１を構成する表面部材１の表面に楔形状の凸部を並列配置し、裏面部材１’は図５（ｂ）の角錐形状の場合と同様、表面部材の楔形状と対応する楔形状を形成して表・裏面部材の楔形状の凸部相互間の一定厚さ（幅）内に磁性粉末材料Ａ２を充填・封入する。或は、裏面部材１’の表面全面を平坦面に形成し、表面部材における楔形状の空間部分が充填空間となり、楔形状の充填空間全体に磁性粉末材料を充填・封入して電波吸収体が完成される。 In FIG. 5C, wedge-shaped convex portions are arranged in parallel on the surface of the surface member 1 constituting the container A1, and the back surface member 1 ′ is a wedge of the surface member as in the case of the pyramid shape in FIG. A wedge shape corresponding to the shape is formed, and the magnetic powder material A2 is filled and enclosed within a certain thickness (width) between the wedge-shaped convex portions of the front and back members. Alternatively, the entire surface of the back surface member 1 ′ is formed as a flat surface, and the wedge-shaped space portion of the surface member becomes a filling space, and the whole of the wedge-shaped filling space is filled and sealed with a magnetic powder material to form a radio wave absorber. Completed.

本発明を以下の実施例により更に詳細に説明する。尚、本発明はそれらに限定されるものではない。
［実施例１］
容器Ａ１を構成する表面部材１と裏面部材１’を、不飽和ポリエステル樹脂にガラス繊維を補強材として混入したＦＲＰにより厚さ１ｍｍの中空成形品を作成した。
その容器Ａ１は、縦及び横が３００ｍｍの正方形の表面に、大円錐形（底面：φ５６、高さ：６７ｍｍ）を２５個、小円錐形（底面：φ２２、高さ：１８．５ｍｍ）を１６個、図２に示すように配置形成し、大円錐形部分は図３、小円錐形部分は図４に示す構成とした。
そして、前記容器Ａ１の表面部材１と裏面部材１’との隙間の厚さ（幅）は７ｍｍ、５ｍｍ、３ｍｍの３種類を用意し、その隙間に充填する磁性粉末材料として下記の３種類を用意した。尚、下記３種類の磁性粉末材料の粒径の大きさは、何れも平均粒径１００μｍで一定のものを使用する。
（Ａ）Ｎｉ‐Ｚｎ系フェライト粉末
（Ｂ）Ｍｇ‐Ｚｎ系フェライト粉末
（Ｃ）砂鉄 The invention is illustrated in more detail by the following examples. In addition, this invention is not limited to them.
[Example 1]
A hollow molded product having a thickness of 1 mm was prepared from the front member 1 and the rear member 1 ′ constituting the container A1 by FRP in which glass fibers were mixed as a reinforcing material in an unsaturated polyester resin.
The container A1 has 25 large conical shapes (bottom surface: φ56, height: 67 mm) and 16 small conical shapes (bottom surface: φ22, height: 18.5 mm) on a square surface of 300 mm in length and width. 2 and arranged as shown in FIG. 2. The large cone portion is configured as shown in FIG. 3, and the small cone portion is configured as shown in FIG.
And the thickness (width) of the gap between the front surface member 1 and the back surface member 1 ′ of the container A1 is prepared in three types of 7 mm, 5 mm, and 3 mm, and the following three types are used as magnetic powder materials to fill the gap. Prepared. In addition, the following three kinds of magnetic powder materials are all used with a constant average particle diameter of 100 μm.
(A) Ni-Zn ferrite powder (B) Mg-Zn ferrite powder (C) Sand iron

上記容器の表面部材の平面視面積（３００×３００）における大円錐形部と小円錐部の底面の面積を除いた平面部の占める割合は２１．８％である。
上記容器Ａ１として、表面部材と裏面部材の隙間の厚さ（幅）が７ｍｍの容器を用い、その容器に磁性粉末材料として上記（Ａ）、（Ｂ）、（Ｃ）を充填封入した電波吸収体を製作し、電波吸収特性を測定した。その充填封入する磁性粉末材料の違いによる電波吸収特性を図６に示す。
又、磁性粉末材料として「イルメナイト粉末」、「砂鉄」、「フェライト粉末」を充填封入し場合の電波吸収特性の違いを図７に示す。 The ratio of the flat portion excluding the areas of the bottom surface of the large cone portion and the small cone portion in the planar view area (300 × 300) of the surface member of the container is 21.8%.
As said container A1, the thickness (width) of the gap between the front surface member and the back surface member is 7 mm, and the container is filled with (A), (B), (C) as a magnetic powder material, and the radio wave absorption is enclosed. The body was manufactured and the radio wave absorption characteristics were measured. FIG. 6 shows the radio wave absorption characteristics depending on the magnetic powder material to be filled and sealed.
Further, FIG. 7 shows the difference in radio wave absorption characteristics when “ilmenite powder”, “sand iron”, and “ferrite powder” are filled and sealed as magnetic powder materials.

また、表面部材と裏面部材との隙間の厚さ（幅）が７ｍｍ一定の容器Ａ１に、磁性粉末材料としてフェライト粉末を充填封入した電波吸収体と、フェライトタイル（厚さ：５．７ｍｍ）単体と、電波吸収体をフェライトタイルに積層した複合体の３種について、電波吸収特性を測定した。その測定した電波吸収特性を図８にします。
同図より明らかなように、フェライトタイル単体より本発明に係る電波吸収体の方が性能特性に優れることが理解できる。更に、フェライトタイルとの複合体とすることで、周波数１〜５．５ＧＨｚの範囲で吸収特性が良くなる傾向にあることが理解される。 Further, a radio wave absorber in which a ferrite powder as a magnetic powder material is filled and enclosed in a container A1 having a constant thickness (width) of 7 mm between the front surface member and the back surface member, and a ferrite tile (thickness: 5.7 mm) alone The radio wave absorption characteristics of three types of composites in which a radio wave absorber is laminated on a ferrite tile were measured. Fig. 8 shows the measured radio wave absorption characteristics.
As is apparent from the figure, it can be understood that the radio wave absorber according to the present invention is superior in performance characteristics to the ferrite tile alone. Furthermore, it is understood that the absorption characteristics tend to be improved in the frequency range of 1 to 5.5 GHz by using a composite with a ferrite tile.

又、容器Ａ１は表面部材に大円錐形と小円錐形を組み合わせ配置した電波入射面平面部分の大きさ（全体に占める平面部の割合）が２１．８％のものであるが、その容器における平面部分の大きさが、電波吸収特性にどのように影響するかを実験した。その比較のために、平面部分の大きさが３２．９％、４５．５％の容器を用意した。
平面部分の大きさが３２．９％の容器は、前記容器Ａ１の表面部材の凸部形状を大円錐形（底面：φ５６、高さ：６７ｍｍ）のみとし、小円錐形が形成されていないもの。
平面部分の大きさが４５．５％の容器は、容器Ａ１における表面部材の凸部形状を大円錐形（底面：φ５０、高さ：６０ｍｍ）のみとし、格子状に２５個配置形成したもの。
そして、上記平面部分の異なる３種の容器（表面部材と裏面部材の隙間の厚さ（幅）は７ｍｍ一定）に、平均粒径が１００μｍ一定のフェライト粉末を充填封入して電波吸収体を製作し、それをフェライトタイルに積層して複合体としたものについて、電波吸収特性を測定した。その測定結果を図９に示す。
図９から明らかなように、周波数１〜３．７ＧＨｚの範囲内において平面部分が少なくなるにともない電波吸収特性が良くなる傾向にあることが理解される。 In addition, the container A1 has a radio wave incident surface plane portion (a ratio of the plane portion occupying in the whole) having a large conical shape and a small conical shape arranged on the surface member in a ratio of 21.8%. An experiment was conducted to determine how the size of the planar portion affects the radio wave absorption characteristics. For the comparison, a container having a plane portion size of 32.9% and 45.5% was prepared.
A container having a planar portion size of 32.9% has a convex shape of the surface member of the container A1 only having a large conical shape (bottom surface: φ56, height: 67 mm), and no small conical shape is formed. .
A container having a flat portion with a size of 45.5% has a convex shape of the surface member of the container A1 only having a large conical shape (bottom surface: φ50, height: 60 mm), and is formed in a lattice shape by 25 pieces.
A radio wave absorber is manufactured by filling and encapsulating ferrite powder with an average particle diameter of 100 μm in the three kinds of containers having different flat portions (the thickness (width) of the gap between the front surface member and the back surface member is constant 7 mm). Then, the radio wave absorption characteristics of the composite material obtained by laminating it on the ferrite tile were measured. The measurement results are shown in FIG.
As is apparent from FIG. 9, it is understood that the radio wave absorption characteristics tend to improve as the plane portion decreases within the frequency range of 1 to 3.7 GHz.

また、平面部分の大きさが４５．５％の容器において、表面部材と裏面部材の隙間の厚さ（幅）が７ｍｍ、５ｍｍ、３ｍｍの３種類を用意し、それらに平均粒径が１００μｍ一定のフェライト粉末を充填封入して電波吸収体を製作し、それをフェライトタイルに積層して複合体としたものについて、電波吸収特性を測定した。その測定結果を図１０に示す。
図１０から明らかなように、磁性粉末材料を充填封入する隙間の厚さ（幅）が厚くなるほど、電波吸収特性は良くなる傾向にあることが理解される。 In addition, in a container having a plane portion size of 45.5%, three types of thickness (width) of the gap between the front surface member and the back surface member of 7 mm, 5 mm, and 3 mm are prepared, and the average particle diameter is constant at 100 μm. A radio wave absorber was manufactured by filling and encapsulating the ferrite powder, and the radio wave absorption characteristic was measured for a composite obtained by laminating the powder absorber on a ferrite tile. The measurement results are shown in FIG.
As is apparent from FIG. 10, it is understood that the radio wave absorption characteristics tend to improve as the thickness (width) of the gap filled and sealed with the magnetic powder material increases.

又、本発明に係る電波吸収体は、容器に磁性粉末材料をそのまま充填封入して構成するが、その充填封入する磁性粉末材料の粒径の大きさの違いにより、電波吸収特性がどのように変わるかを実験した。
使用する容器は、平面部分の大きさが２１．８％で、表面部材と裏面部材の隙間の厚さ（幅）が７ｍｍの容器を用い、これに平均粒径が１００μｍ、２００μｍ、４００μｍと粒径の大きさが異なるフェライト粉末（磁性粉末材料）を充填封入して電波吸収体を製作し、それをフェライトタイルに積層して複合体としたものについて、電波吸収特性を測定した。その測定結果を図１１に示す。
図１１から明らかなように、周波数５０〜３００ＭＨｚの範囲において、充填封入する磁性粉末材料の粒径は、大きさが小さくなるほど、電波吸収特性は良くなる傾向にあることが理解される。 Further, the radio wave absorber according to the present invention is directly constituted by filling enclosed magnetic powder material into the container, the difference in size of the particle diameter of the magnetic powder material to the filling enclosed, how wave absorption characteristics Experimented to change.
As the container to be used, a container having a plane portion size of 21.8% and a thickness (width) of a gap between the front surface member and the back surface member of 7 mm is used, and the average particle size is 100 μm, 200 μm, and 400 μm. A radio wave absorber was manufactured by filling and encapsulating ferrite powders (magnetic powder materials) having different diameters, and the radio wave absorption characteristics were measured for a composite obtained by laminating it on a ferrite tile. The measurement results are shown in FIG.
As can be seen from FIG. 11, in the frequency range of 50 to 300 MHz, it is understood that the particle size of the magnetic powder material to be filled and sealed tends to improve the radio wave absorption characteristics as the size decreases.

本発明に係る電波吸収体の実施の一例を示す斜視図。The perspective view which shows an example of implementation of the electromagnetic wave absorber which concerns on this invention. 同平面図。FIG. 図２の（３）−（３）線に沿える拡大断面図。The expanded sectional view which follows the (3)-(3) line | wire of FIG. 図２の（４）−（４）線に沿える拡大断面図。The expanded sectional view which follows the (4)-(4) line | wire of FIG. （ａ）、（ｂ）、（ｃ）は電波吸収体を構成する容器の他の形状を示す。(A), (b), (c) shows the other shape of the container which comprises an electromagnetic wave absorber. 容器に充填する磁性粉末材料の違いによる電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic by the difference in the magnetic powder material with which a container is filled. 容器に充填する磁性粉末材料の違いによる電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic by the difference in the magnetic powder material with which a container is filled. 本発明に係る電波吸収体単体、電波吸収体とフェライトタイルとの複合体、及びフェライトタイル単体の電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic of the electromagnetic wave absorber simple substance concerning this invention, the composite_body | complex of an electromagnetic wave absorber and a ferrite tile, and a ferrite tile simple substance. 電波吸収体を構成する容器の平面部分の大きさによる電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic by the magnitude | size of the plane part of the container which comprises an electromagnetic wave absorber. 電波吸収体を構成する容器の充填空間の変化による電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic by the change of the filling space of the container which comprises an electromagnetic wave absorber. 電波吸収体の容器に充填する磁性粉末材料の粒径の大きさによる電波吸収特性を示す線図。The diagram which shows the electromagnetic wave absorption characteristic by the magnitude | size of the particle size of the magnetic powder material with which the container of an electromagnetic wave absorber is filled.

符号の説明Explanation of symbols

Ａ…電波吸収体Ａ１…容器
Ａ２…磁性粉末材料１…表面部材
１’…裏面部材２、２’…大円錐形
３…小円錐形３’…平坦面 A ... Absorber A1 ... Container A2 ... Magnetic powder material 1 ... Surface member 1 '... Back member 2,2' ... Large cone 3 ... Small cone 3 '... Flat surface

Claims

電波の入射方向と対向する表面部材と、その表面部材の裏側に接合する裏面部材からなり、
前記表面部材が非導電性材料で構成され、表面に円錐、角錐、或いは楔形状の凹凸を有し、
前記裏面部材が前記表面部材と略一定の充填空間を区画形成するよう少なくとも一部に前記表面部材に対応して表面に円錐、角錐、或いは楔形状の凹凸を有する容器に、
磁性粉末材料をそのまま充填、封入したことを特徴とする電波吸収体。 It consists of a surface member facing the incident direction of the radio wave and a back surface member joined to the back side of the surface member,
The surface member is made of a non-conductive material, and has conical, pyramidal, or wedge-shaped irregularities on the surface,
A container having conical, pyramid, or wedge-shaped irregularities on the surface corresponding to the surface member at least partially so that the back surface member defines a substantially constant filling space with the surface member .
An electromagnetic wave absorber characterized by being filled and encapsulated with a magnetic powder material.

前記容器に充填・封入する磁性粉末材料は、フェライト、カルボニル鉄、軟磁性金属、磁鉄鉱（砂鉄）、及びイルメナイトの磁性損失を有することを特徴とする請求項１記載の電波吸収体。 2. The radio wave absorber according to claim 1, wherein the magnetic powder material filled and sealed in the container has magnetic loss of ferrite, carbonyl iron, soft magnetic metal, magnetite (sand iron), and ilmenite.

前記容器を構成する表面部材の非導電性材料は、熱硬化性樹脂、熱可塑性樹脂、ゴム系の合成樹脂或いはセラミックスからなり、更に裏面部材は前記非導電性材料或いは金属、カーボン材の導電性材料からなり、前記表面部材の厚さが０．１〜５ｍｍの範囲にあることを特徴とする請求項１又は２記載の電波吸収体。 The non-conductive material of the surface member constituting the container is made of thermosetting resin, thermoplastic resin, rubber-based synthetic resin or ceramics, and the back member is conductive of the non-conductive material, metal, or carbon material. 3. The radio wave absorber according to claim 1, wherein the wave absorber is made of a material, and the thickness of the surface member is in a range of 0.1 to 5 mm.

前記容器の円錐形状は、大円錐部を格子状に配置し、その大円錐部で囲まれた中央部に小円錐部を配置したことを特徴とする請求項１乃至３いずれか１項記載の電波吸収体。 4. The container according to claim 1, wherein the container has a conical shape in which a large cone portion is arranged in a lattice shape, and a small cone portion is arranged in a central portion surrounded by the large cone portion . Radio wave absorber.

前記請求項１乃至４記載の電波吸収体を、フェライトタイルの上面に接合したことを特徴とする電波吸収体。 5. A radio wave absorber comprising the radio wave absorber according to claim 1 bonded to an upper surface of a ferrite tile .