JPH06104632A - Anechoic chamber - Google Patents
Anechoic chamberInfo
- Publication number
- JPH06104632A JPH06104632A JP4272553A JP27255392A JPH06104632A JP H06104632 A JPH06104632 A JP H06104632A JP 4272553 A JP4272553 A JP 4272553A JP 27255392 A JP27255392 A JP 27255392A JP H06104632 A JPH06104632 A JP H06104632A
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- Prior art keywords
- floor
- anechoic chamber
- radio wave
- waveguide
- section
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車や航空機等に取
り付けた受信アンテナ及び移動体通信用のアンテナ等の
特性測定、並びに電子機器から発生する不要電波やノイ
ズ等を評価するための及び外部からの妨害電波による電
子機器への影響を試験するＥＭＩやＥＭＳの測定に用い
る電波暗室に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for measuring the characteristics of receiving antennas and mobile communication antennas mounted on automobiles, aircrafts, etc., and for evaluating unnecessary radio waves and noises generated from electronic devices and externally. The present invention relates to an anechoic chamber used for measuring EMI and EMS, which tests the influence of radio waves from EMI on electronic devices.
【０００２】[0002]
【従来の技術】従来から、アンテナ等に関する電波伝搬
特性の測定、電子機器から発生するノイズ評価測定や外
部からの妨害電波による電子機器への影響に対する試験
を行う環境として、気象条件、温湿度条件、外来ノイズ
の影響を除去でき、安定かつ信頼度の高い室内空間が望
まれている。電波暗室は、このような室内空間を提供す
べく、その壁面、天井、及び床面を電波吸収体で覆った
ものであり、その優秀性はよく知られており、広く応用
されている。2. Description of the Related Art Conventionally, as an environment for measuring the radio wave propagation characteristics of an antenna, measuring the noise generated from an electronic device, and testing the influence of an interference wave from the outside on the electronic device, weather conditions, temperature and humidity conditions have been used. A stable and highly reliable indoor space that can remove the influence of external noise is desired. The anechoic chamber is one in which the wall surface, ceiling, and floor surface are covered with an electromagnetic wave absorber in order to provide such an indoor space, and its superiority is well known and widely applied.
【０００３】このような電波暗室の特性としては、電波
的に全く障害が無い自由空間を室内で実現することが大
きな課題となっており、室内の側壁面、天井面、及び床
面から反射する不要な電磁波エネルギを少なくするこ
と、及び優れた電界均一性を受信部で得ることが望まれ
ている。As a characteristic of such an anechoic chamber, it is a major issue to realize a free space in the room free from radio wave obstructions, and it is reflected from the side wall surface, ceiling surface and floor surface of the room. It is desired to reduce unnecessary electromagnetic wave energy and to obtain excellent electric field uniformity in the receiver.
【０００４】なお、自由空間における電波伝搬特性と
は、電波発生源である送信アンテナをモデル的に点波源
とした場合に、放射された電波の電界が同心球状に広が
って伝搬していき、十分な遠方の限られた領域において
大きさ及び位相が面内でそろったいわゆる平面波が実現
されることにより電界均一性が確保されるごときもので
ある。ただし、十分な遠方では、伝搬距離が長くなるに
従ってその距離に逆比例して電界強度が減衰する。Incidentally, the radio wave propagation characteristic in free space means that when the transmission antenna, which is a radio wave generation source, is modeled as a point wave source, the electric field of the radiated radio wave spreads concentrically and propagates sufficiently. The electric field uniformity is ensured by realizing a so-called plane wave in which the magnitude and phase are aligned in the plane in a limited region at a long distance. However, at a sufficiently long distance, as the propagation distance increases, the electric field strength attenuates in inverse proportion to the distance.
【０００５】電波暗室は、一般的な直方体形状のものの
他に、送信部及び受信部の中間領域の壁面、天井面、及
び床面を広くしてそこからの反射を少なくした形状のも
の、さらに最近では狭い空間の送信部と広い空間の受信
部とをテーパ形状の導波部で連結したテーパ型電波暗室
が開発されている。The anechoic chamber has, in addition to a general rectangular parallelepiped shape, a shape in which a wall surface, a ceiling surface, and a floor surface in an intermediate region between the transmitting portion and the receiving portion are widened to reduce reflection from them. Recently, a tapered anechoic chamber has been developed in which a transmitter in a narrow space and a receiver in a wide space are connected by a tapered waveguide.
【０００６】テーパ型電波暗室は、直方体形状の電波暗
室に比べて、同一の送受信間距離をとった場合により少
ない容積で構成できるため経済的である。また、導波部
においてそのテーパ角度故に側壁部からの反射の影響が
ほとんどなく、送信部において側壁反射波の行路差を小
さくできるのでその位相差が極めて小さくなるから受信
部での電界均一性が優秀となる。The taper type anechoic chamber is economical because it can be constructed with a smaller volume when the same transmitting and receiving distance is taken, as compared with a rectangular anechoic chamber. In addition, because of the taper angle of the waveguide portion, there is almost no influence of reflection from the sidewall portion, and the path difference of the sidewall reflected wave can be reduced in the transmission portion, so that the phase difference is extremely small and therefore the electric field uniformity in the reception portion is reduced. Become excellent.
【０００７】図７は従来のこの種テーパ型電波暗室を概
略的に表す平面図、図８は図７のVIII−VIII線断面図で
ある。FIG. 7 is a plan view schematically showing the conventional taper type anechoic chamber of this kind, and FIG. 8 is a sectional view taken along line VIII-VIII of FIG.
【０００８】これらの図に示すように、従来のテーパ型
電波暗室は、その平面形状及び側断面形状が共にテーパ
形状となっており、その全ての壁面、即ち側壁面７０、
天井面７１、及び床面７２が抵抗損失材料であるカーボ
ン含有発泡体からなるピラミッド形状又はウェッジ形状
の電波吸収体７３で覆われている。狭い空間の送信部７
４の端部には導波管を有するホーンアンテナ式の発信構
造７５が設けられている。この送信部７４と広い空間の
受信部７６とは、テーパ状の導波部７７によって連結さ
れている。導波部７７は、その側壁面、天井面、及び床
面が、送信部７４から受信部７６に向かって徐々に広が
り断面積が徐々に大きくなるごときテーパ形状となって
いる。As shown in these drawings, the conventional tapered anechoic chamber has a tapered planar shape and a side sectional shape, and all the wall surfaces, that is, the side wall surfaces 70,
The ceiling surface 71 and the floor surface 72 are covered with a pyramid-shaped or wedge-shaped radio wave absorber 73 made of a carbon-containing foam which is a resistance loss material. Narrow space transmitter 7
A horn antenna type transmitting structure 75 having a waveguide is provided at the end of 4. The transmitting section 74 and the receiving section 76 having a wide space are connected by a tapered waveguide section 77. The waveguide 77 has a side wall surface, a ceiling surface, and a floor surface that are tapered so that the cross-sectional area gradually expands from the transmitter 74 to the receiver 76.
【０００９】[0009]
【発明が解決しようとする課題】自動車等の地上移動体
に搭載されているアンテナが実装状態で電波受信する場
合、大地からの反射波と送信源からの直接波とを合成し
た電波を受け取ることとなる。しかしながら、上述した
ごとき従来のテーパ型電波暗室では、床面も電波吸収体
で構成されているので、大地からの反射波が無く直接波
だけを受け取ることとなる。このため、電波暗室内で受
信した電波特性と実用状態の電波特性とが互いに異なっ
てしまう。When an antenna mounted on a ground moving body such as an automobile receives a radio wave in a mounted state, it must receive a radio wave that is a combination of a reflected wave from the ground and a direct wave from a transmission source. Becomes However, in the conventional taper type anechoic chamber as described above, since the floor surface is also constituted by the electromagnetic wave absorber, there is no reflected wave from the ground and only the direct wave is received. Therefore, the radio wave characteristic received in the anechoic chamber and the radio wave characteristic in the practical state are different from each other.
【００１０】また、従来のテーパ型電波暗室では抵抗損
失材料による電波吸収体を用いているため、優れた電波
吸収特性を得るためには、電波吸収体の長さを吸収すべ
き周波数の波長の少なくとも１／２以上とする必要があ
る。これは、吸収すべき周波数を例えば１００ＭＨｚと
した場合、吸収体の長さが１．５ｍ以上となり、電波暗
室を構成する建屋の大きさが著しく大きくなって経済的
に不利となると共に各壁面からの電波吸収体の先端間に
挟まれる有効空間の容積が非常に小さくなってしまう。Further, in the conventional taper type anechoic chamber, since the electromagnetic wave absorber made of the resistance loss material is used, in order to obtain excellent electromagnetic wave absorption characteristics, the length of the electromagnetic wave absorber is set to the wavelength of the frequency to be absorbed. It should be at least 1/2 or more. This is because, if the frequency to be absorbed is 100 MHz, for example, the length of the absorber will be 1.5 m or more, the size of the building that constitutes the anechoic chamber will be significantly large, and it will be economically disadvantageous and from each wall surface. The volume of the effective space sandwiched between the tips of the radio wave absorbers becomes extremely small.
【００１１】さらに、従来のテーパ型電波暗室では、送
信部の発信構造からその発信周波数範囲が導波管の周波
数範囲に限定されてしまう。このため、最近の電波利用
の拡大及び利用周波数の広帯域化に伴って広帯域の測定
を行う場合には、周波数帯域の互いに異なる複数の送信
部を用意してこれらを交換することが必要となり、これ
は経済的な負担を増すのみならず交換に多大な手間がか
かるという不都合を招く。Further, in the conventional taper type anechoic chamber, the transmission frequency range of the transmitting section is limited to the frequency range of the waveguide. For this reason, when performing wideband measurements with the recent expansion of radio wave usage and widening of available frequencies, it is necessary to prepare a plurality of transmitters having different frequency bands and exchange them. Causes an inconvenience that not only increases the financial burden but also requires a great deal of labor for replacement.
【００１２】従って本発明は、従来技術の上述の問題点
を解決するものであり、優れた電波暗室性能を有すると
共に広い内部空間を確保できかつ安価に形成することの
できる電波暗室を提供するものである。Therefore, the present invention solves the above-mentioned problems of the prior art, and provides an anechoic chamber which has excellent anechoic chamber performance, can secure a wide internal space, and can be formed at low cost. Is.
【００１３】[0013]
【課題を解決するための手段】本発明によれば、送信部
及び受信部の壁面を電波吸収体で覆い、これら送信部及
び受信部をテーパ状の導波部で連結したテーパ型の電波
暗室であって、導波部の床面を大地等価床で構成し、そ
の導波部の天井面及び側壁面の少なくとも一部をフェラ
イト電波吸収体で構成した電波暗室が提供される。According to the present invention, the wall surface of the transmitter and the receiver is covered with a radio wave absorber, and the transmitter and the receiver are connected by a tapered wave guide. An anechoic chamber is provided in which the floor surface of the waveguide section is formed of a ground equivalent floor, and at least a part of the ceiling surface and side wall surface of the waveguide section is formed of a ferrite electromagnetic wave absorber.
【００１４】送信部、導波部、及び受信部の床面を大地
に対して平坦な構造とし、受信部及び導波部の床面をフ
ェライトタイルと導電性フィルムとを組み合わせてなる
大地等価床で構成することが好ましい。A floor equivalent to a ground equivalent floor in which the floor surfaces of the transmitter, the waveguide, and the receiver are flat with respect to the ground, and the floor of the receiver and the waveguide are combined with a ferrite tile and a conductive film. It is preferable that
【００１５】送信部及び受信部の壁面に配置する電波吸
収体をフェライトタイルと抵抗損失材料との組み合わせ
からなる複合型電波吸収体で構成することも好ましい。It is also preferable that the electromagnetic wave absorbers arranged on the wall surfaces of the transmitting section and the receiving section are composed of a composite type electromagnetic wave absorber made of a combination of a ferrite tile and a resistance loss material.
【００１６】送信部に独立した送信用広帯域アンテナを
配置することも本発明の一実施態様である。It is also an embodiment of the present invention to dispose an independent transmitting broadband antenna in the transmitting section.
【００１７】[0017]
【作用】送信部と受信部とをテーパ状の導波部で連結
し、野外における実用状態の電波環境と同一の環境を形
成するため、導波部の床面を大地と電波的に等価な特性
を有する大地等価床で構成している。そして、導波部の
天井面及び側壁面の一部又は全部を、波長の１／２以上
の長さを有する抵抗損失材料による電波吸収体の代わり
に、フェライト電波吸収体を配置している。フェライト
電波吸収体は、大きな磁気損失を有しており、波長の１
／５０〜１／２００の厚さで優れた電波吸収性能を有し
ているので、より広い有効空間を確保できると共に電波
暗室を安価に形成することができる。[Function] Since the transmitter and the receiver are connected by the tapered waveguide to form the same environment as the radio environment in the outdoor practical state, the floor of the waveguide is radio equivalent to the ground. It is composed of a ground equivalent floor with characteristics. Further, a ferrite wave absorber is arranged on part or all of the ceiling surface and the side wall surface of the waveguide section instead of the wave absorber made of a resistance loss material having a length of ½ or more of the wavelength. The ferrite wave absorber has a large magnetic loss, and
Since it has an excellent electromagnetic wave absorption performance with a thickness of / 50 to 1/200, a wider effective space can be secured and an anechoic chamber can be formed at low cost.
【００１８】[0018]
【実施例】以下本発明の実施例を詳細に説明する。EXAMPLES Examples of the present invention will be described in detail below.
【００１９】図１は本発明の電波暗室の一実施例の構成
を概略的に示す平面図であり、図２は図１のII−II線断
面図である。FIG. 1 is a plan view schematically showing the construction of an embodiment of the anechoic chamber of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG.
【００２０】これらの図に示すように、テーパ型電波暗
室１０は、その一端部を狭い空間の送信部１１として構
成し、他端部を広い空間の受信部１２として構成してい
る。この送信部１１は、その壁面からの不要反射波を極
力抑えることにより、できるだけ単一モードの電波が伝
送されるように設計されている。送信部１１の床面を除
く４つの壁面、即ち左右の側壁面１１ａ及び１１ｂ、天
井面１１ｃ、奥壁面１１ｄは、フェライト電波吸収体と
抵抗損失材料とを組み合わせてなる複合型電波吸収体１
３で覆われている。また、受信部１２は、伝送されてき
た電波をあたかも無限空間が続いている状況を再現する
ためにその壁面からの不要反射波を極力抑え、進行波成
分のみが受信領域で得られるように設計されている。受
信部１２の床面を除く４つの壁面、即ち左右の側壁面１
２ａ及び１２ｂ、天井面１２ｃ、奥壁面１２ｄも、フェ
ライト電波吸収体と抵抗損失材料とを組み合わせてなる
複合型電波吸収体１４で覆われている。これら電波吸収
体１３及び１４は、ピラミッド形状、ウェッジ形状、又
は材料定数が厚さ方向に異なる板形状に構成されてい
る。As shown in these figures, the tapered anechoic chamber 10 has one end as a transmitting portion 11 having a narrow space and the other end having a receiving portion 12 having a wide space. The transmitter 11 is designed to transmit a single-mode radio wave as much as possible by suppressing unnecessary reflected waves from its wall surface. The four wall surfaces other than the floor surface of the transmitter 11, that is, the left and right side wall surfaces 11a and 11b, the ceiling surface 11c, and the inner wall surface 11d are the composite electromagnetic wave absorber 1 formed by combining a ferrite electromagnetic wave absorber and a resistance loss material.
Covered with 3. In addition, the receiving unit 12 is designed so that unnecessary reflected waves from the wall surface are suppressed as much as possible in order to reproduce the situation in which an infinite space continues for the transmitted electric wave, and only the traveling wave component is obtained in the receiving area. Has been done. Four wall surfaces other than the floor surface of the receiver 12, that is, the left and right side wall surfaces 1
2a and 12b, the ceiling surface 12c, and the back wall surface 12d are also covered with the composite type electromagnetic wave absorber 14 made of a combination of a ferrite electromagnetic wave absorber and a resistance loss material. The radio wave absorbers 13 and 14 are formed in a pyramid shape, a wedge shape, or a plate shape having different material constants in the thickness direction.
【００２１】このように電波吸収体１３及び１４とし
て、フェライト電波吸収体と抵抗損失材料とを組み合わ
せた複合型電波吸収体を用いているため、低周波から優
れた電波吸収特性が得られると共に抵抗損失材料だけで
構成した場合に比して１／２以下の長さで同等以上の吸
収特性を得ることができる。その結果、電波暗室内の有
効空間が広がるのみならず建屋自体も小さくでき全体と
してコストを大幅に低減することができる。As described above, since the composite type electromagnetic wave absorber in which the ferrite electromagnetic wave absorber and the resistance loss material are combined is used as the electromagnetic wave absorbers 13 and 14, excellent electromagnetic wave absorption characteristics can be obtained from low frequencies and the resistance can be improved. It is possible to obtain equal or more absorption characteristics with a length of ½ or less as compared with the case where only the lossy material is used. As a result, not only the effective space in the anechoic chamber can be expanded, but also the building itself can be made small and the cost can be largely reduced as a whole.
【００２２】送信部１１と受信部１２とは、テーパ形状
の導波部１５で接続されている。この導波部１５は、送
信部１１から伝送された単一モードの電波を壁面の局部
的不均一性による反射をできるだけなくし、かつ短い伝
送距離で自由空間における遠方領域の電波伝搬特性に近
い状況を得るためにできるだけ高い電波減衰効果を得る
ように設計されている。導波部１５の床面を除く３つの
壁面、即ち左右の側壁面１５ａ及び１５ｂ、天井面１５
ｃの全部又は一部は、平板状のフェライト電波吸収体１
６で構成されている。このフェライト電波吸収体１６
は、大きな磁気損失を有しており広帯域で電波減衰効果
が大きいものであり、また、波長の１／５０〜１／２０
０の厚さであっても優れた電波吸収性能を有しているの
で、極めて薄型に構成することができる。その結果、よ
り短い伝搬距離で電界均一な特性が得られると共に広い
有効空間を確保できしかも経済的な小さい建屋で有効な
電波暗室を実現することができる。The transmitter 11 and the receiver 12 are connected by a tapered waveguide 15. The waveguide unit 15 minimizes the reflection of the single mode radio wave transmitted from the transmission unit 11 due to the local non-uniformity of the wall surface, and is close to the radio wave propagation characteristics of the far region in the free space with a short transmission distance. Is designed to obtain the highest possible radio wave attenuation effect. Three wall surfaces except the floor surface of the waveguide section 15, that is, the left and right side wall surfaces 15a and 15b, and the ceiling surface 15
All or part of c is a flat ferrite wave absorber 1
It is composed of 6. This ferrite wave absorber 16
Has a large magnetic loss, has a large radio wave attenuation effect in a wide band, and has a wavelength of 1/50 to 1/20.
Even if the thickness is 0, it has excellent electromagnetic wave absorption performance, so that it can be made extremely thin. As a result, a uniform electric field can be obtained with a shorter propagation distance, a large effective space can be secured, and an effective anechoic chamber can be realized in an economical small building.
【００２３】送信部１１、受信部１２、及び導波部１５
の床面１１ｅ、１２ｅ、及び１５ｅは、大地に対して平
行な平坦構造となっている。これは、一般に大地が平坦
であるためこれに合わせたものである。さらにこれら床
面１１ｅ、１２ｅ、及び１５ｅは、フェライトタイルと
導電性フィルムとを組み合わせることによって大地と電
波的に等価な特性を有する大地等価床となっている。The transmitter 11, the receiver 12, and the waveguide 15
The floor surfaces 11e, 12e, and 15e have a flat structure parallel to the ground. This is because the ground is generally flat. Furthermore, these floor surfaces 11e, 12e, and 15e are earth equivalent floors having characteristics equivalent to the earth in terms of radio waves by combining a ferrite tile and a conductive film.
【００２４】送信部１１の中央部には、広帯域特性を有
する独立したアレイ型アンテナ１７が設置されており、
送信部１１全体が広帯域の発信装置として構成される。
このため、周波数帯別の複数の送信部を用意する必要が
なくなり、しかもこれらを交換する手間も省ける。An independent array type antenna 17 having a wide band characteristic is installed at the center of the transmitter 11.
The entire transmitter 11 is configured as a broadband transmitter.
Therefore, it is not necessary to prepare a plurality of transmission units for each frequency band, and the labor for exchanging them can be saved.
【００２５】受信部１２の中央には、被測定物、例えば
自動車Ｗを載置するためのターンテーブル１８が設けら
れている。At the center of the receiver 12, there is provided a turntable 18 on which an object to be measured, for example a car W, is placed.
【００２６】このように本実施例によれば、野外の電波
伝搬環境と条件を同一にするために、大地と電波的に等
価な大地等価床を導波部１５に設けているので、送信部
１１からの直接波と導波部１５の床面１５ｅからの反射
波とが実用状態と同じように合成されて受信部１２へ入
来して野外における電波伝搬に近い受信状態が実現され
る。As described above, according to this embodiment, since the ground equivalent floor, which is radio equivalent to the ground, is provided in the waveguide 15 in order to make the same conditions as the outdoor radio wave propagation environment, the transmitter is provided. The direct wave from 11 and the reflected wave from the floor surface 15e of the waveguide section 15 are combined in the same manner as in the practical state and enter the receiving section 12 to realize a receiving state close to radio wave propagation in the field.
【００２７】床面を大地と電波的に等価な大地等価床と
した場合、送信部１１からの直接波と大地等価床からの
反射波とが互いに干渉して大きな極大値及び極小値を有
するリップル現象の生じる可能性があり、互いの干渉に
よる電界不均一性を持たないようにすることが必要とな
る。そのためには、反射波の位相と直接波の位相との差
が少なくとも１／２波長以上となるように送受信間距離
を選ぶ必要がある。When the floor surface is a ground equivalent floor that is radio equivalent to the ground, the direct wave from the transmitter 11 and the reflected wave from the ground equivalent floor interfere with each other and have ripples having large maximum and minimum values. This may cause a phenomenon, and it is necessary to prevent electric field nonuniformity due to mutual interference. For that purpose, it is necessary to select the distance between transmission and reception such that the difference between the phase of the reflected wave and the phase of the direct wave is at least ½ wavelength or more.
【００２８】図３に示すように、送信アンテナ３０の高
さをｈ1 、受信アンテナ３１の高さをｈ2 、送受信アン
テナ間の直線距離をｌ0 、送受信アンテナ間の反射距離
をｌ1 及びｌ2 、波長をλとすると、これは、 ｌ1 ＋ｌ2 −ｌ0 ＝√｛ｌ0 2 ＋（ｈ1 ＋ｈ2 ）2 ｝−ｌ0 ≧λ／２ の関係を満たすこととなる。例えば、送信アンテナ３０
の高さｈ1 と受信アンテナ３１の高さｈ2 との和がｈ1
＋ｈ2 ＝３ｍの場合、送受信アンテナ間の直線距離ｌ0
は、周波数を１００ＭＨｚとするとｌ0 ≧２．２５ｍと
なり、周波数を３００ＭＨｚとするとｌ0 ≧８．７５ｍ
となり、周波数を６００ＭＨｚとするとｌ0 ≧１７．９
ｍとなる。また、ｈ1 ＋ｈ2 ＝４ｍの場合、周波数を１
００ＭＨｚとするとｌ0 ≧４．５８ｍとなり、周波数を
３００ＭＨｚとするとｌ0 ≧１５．７５ｍとなり、周波
数を６００ＭＨｚとするとｌ0 ≧３２ｍとなる。このよ
うな条件を満たすように設定すると、受信アンテナが実
用上遠方にある送信点から電波を受けるという電波伝搬
の環境が実現される。As shown in FIG. 3, the height of the transmitting antenna 30 is h 1 , the height of the receiving antenna 31 is h 2 , the linear distance between the transmitting and receiving antennas is l 0 , the reflecting distance between the transmitting and receiving antennas is l 1, and If l 2 and the wavelength are λ, this satisfies the relation of l 1 + l 2 −l 0 = √ {l 0 2 + (h 1 + h 2 ) 2 } −l 0 ≧ λ / 2. For example, the transmitting antenna 30
Of the height h 1 of the receiving antenna 31 and the height h 2 of the receiving antenna 31 is h 1
When + h 2 = 3 m, the linear distance l 0 between the transmitting and receiving antennas
Is l 0 ≧ 2.25 m when the frequency is 100 MHz, and l 0 ≧ 8.75 m when the frequency is 300 MHz
Therefore, if the frequency is 600 MHz, then l 0 ≧ 17.9
m. When h 1 + h 2 = 4 m, the frequency is set to 1
At 00 MHz, l 0 ≧ 4.58 m, at frequency 300 MHz, l 0 ≧ 15.75 m, and at frequency 600 MHz, l 0 ≧ 32 m. Setting to satisfy such a condition realizes a radio wave propagation environment in which the reception antenna receives a radio wave from a transmission point which is practically distant.
【００２９】図３及び図４は、上述した実施例のテーパ
型電波暗室１０における周波数に対する電界の変動値特
性を表している。この特性は、高さ１．３ｍで直径６ｍ
の円内における電界分布を示しており、図３が水平偏
波、図４が垂直偏波の場合である。3 and 4 show the variation value characteristics of the electric field with respect to the frequency in the tapered anechoic chamber 10 of the above-described embodiment. This property has a height of 1.3 m and a diameter of 6 m.
3 shows the electric field distribution in the circle, FIG. 3 shows the case of horizontal polarization, and FIG. 4 shows the case of vertical polarization.
【００３０】従来の電波暗室では、最大−最小の電界変
動値が一部の帯域で８ｄＢ以上となることがあったが、
本実施例のテーパ型電波暗室では、最大−最小の電界変
動値が４ｄＢ以下となっており、非常に安定している。In the conventional anechoic chamber, the maximum-minimum electric field fluctuation value may be 8 dB or more in some bands.
In the taper type anechoic chamber of the present embodiment, the maximum-minimum electric field fluctuation value is 4 dB or less, which is very stable.
【００３１】図５は、上述した実施例のテーパ型電波暗
室１０で評価されたダイポールアンテナの水平面パター
ン特性図である。FIG. 5 is a horizontal plane pattern characteristic diagram of the dipole antenna evaluated in the tapered anechoic chamber 10 of the above-described embodiment.
【００３２】同図から明らかのように、本実施例のテー
パ型電波暗室１０によれば、ダイポールアンテナ固有の
８の字特性において電界がゼロに近くなる点、即ちヌル
点が、自由空間における場合と同様に、両側２か所に対
称性をもって現れている。これは、本実施例のテーパ型
電波暗室１０が、回りからの不要反射が極めて少なく自
由空間に近い非常に優れた電波伝搬特性を再現できるこ
とを表している。As is clear from the figure, according to the taper type anechoic chamber 10 of this embodiment, the point where the electric field is close to zero in the figure 8 characteristic of the dipole antenna, that is, the null point, is in the free space. Similarly, the two appear on both sides with symmetry. This means that the tapered anechoic chamber 10 of the present embodiment can reproduce extremely excellent radio wave propagation characteristics close to free space with very little unnecessary reflection from the surroundings.
【００３３】[0033]
【発明の効果】以上詳細に説明したように本発明によれ
ば、少なくとも導波部の床面を大地等価床とすることに
より、野外実相における電波伝搬にほぼ近い特性を得る
ことができる。しかも導波部の天井面及び側壁面の少な
くとも一部をフェライト電波吸収体で構成することによ
り、効果的な電波減衰が得られより短い距離で優れた電
界均一性が得られるので電波暗室性能として優れている
のみならず、極めて短い電波吸収体で構成することがで
きるので広い空間の確保が行えかつ経済的に安価な電波
暗室を提供することができる。また、送信部に広帯域の
アンテナを配置することにより、周波数帯域別の複数の
送信部を用意する必要がなく経済的に低コストとなりし
かも送信部交換の手間が省けるので大幅な省力化及び迅
速化を図ることができる。As described in detail above, according to the present invention, by making at least the floor surface of the waveguide part the ground equivalent floor, it is possible to obtain characteristics close to radio wave propagation in the actual field. Moreover, by constructing at least a part of the ceiling surface and side wall surface of the waveguide part with a ferrite electromagnetic wave absorber, effective electromagnetic wave attenuation can be obtained and excellent electric field uniformity can be obtained in a shorter distance. It is possible to provide an economical anechoic chamber that is not only excellent but can be configured with an extremely short electromagnetic wave absorber so that a wide space can be secured and which is economically inexpensive. Also, by arranging a wideband antenna in the transmitter, there is no need to prepare multiple transmitters for each frequency band, which is economically low in cost, and the labor of replacing the transmitters can be saved, which greatly saves labor and speeds up. Can be achieved.
【図１】本発明の電波暗室の一実施例の構成を概略的に
示す平面図である。FIG. 1 is a plan view schematically showing the configuration of an embodiment of an anechoic chamber of the present invention.
【図２】図１のII−II線断面図である。FIG. 2 is a sectional view taken along line II-II in FIG.
【図３】電波の直接波及び反射波の関係を表した電波伝
搬のモデル図である。FIG. 3 is a model diagram of radio wave propagation showing a relationship between a direct wave and a reflected wave of a radio wave.
【図４】図１及び図２の実施例における電界変動値の安
定性を示す特性図である。FIG. 4 is a characteristic diagram showing the stability of electric field fluctuation values in the examples of FIGS. 1 and 2.
【図５】図１及び図２の実施例における電界変動値の安
定性を示す特性図である。5 is a characteristic diagram showing the stability of electric field fluctuation values in the examples of FIGS. 1 and 2. FIG.
【図６】図１及び図２の実施例の電波暗室で評価された
ダイポールアンテナの水平面パターン特性図である。6 is a horizontal plane pattern characteristic diagram of the dipole antenna evaluated in the anechoic chamber of the embodiment of FIGS. 1 and 2. FIG.
【図７】従来のテーパ型電波暗室を概略的に表す平面図
である。FIG. 7 is a plan view schematically showing a conventional tapered anechoic chamber.
【図８】図７のVIII−VIII線断面図である。8 is a sectional view taken along line VIII-VIII of FIG.
１０ テーパ型電波暗室 １１ 送信部 １１ａ、１１ｂ、１２ａ、１２ｂ、１５ａ、１５ｂ 側
壁面 １１ｃ、１２ｃ 、１５ｃ 天井面 １１ｄ、１２ｄ 奥壁面 １１ｅ、１２ｅ、１５ｅ 床面 １２ 受信部 １３、１４ 複合型電波吸収体 １５ 導波部 １６ フェライト電波吸収体 １７ アレイ型アンテナ １８ ターンテーブル10 Tapered anechoic chamber 11 Transmitter 11a, 11b, 12a, 12b, 15a, 15b Side wall surface 11c, 12c, 15c Ceiling surface 11d, 12d Inner wall surface 11e, 12e, 15e Floor surface 12 Receiver section 13, 14 Combined electromagnetic wave absorption Body 15 Waveguide 16 Ferrite electromagnetic wave absorber 17 Array type antenna 18 Turntable
フロントページの続き (72)発明者 小林 敏昭 東京都中央区日本橋一丁目13番１号ティー ディーケイ株式会社内 (72)発明者 関 慎吾 大阪府大阪市中央区道修町３丁目５番11号 日本板硝子株式会社内 (72)発明者 小川 一彦 大阪府大阪市中央区道修町３丁目５番11号 日本板硝子株式会社内 (72)発明者 村上 治憲 大阪府大阪市中央区道修町３丁目５番11号 日本板硝子株式会社内 (72)発明者 田中 啓介 大阪府大阪市中央区道修町３丁目５番11号 日本板硝子株式会社内Front page continuation (72) Toshiaki Kobayashi Toshiaki Kobayashi 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Shingo Seki 3-5-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka Japan Sheet Glass Incorporated (72) Inventor Kazuhiko Ogawa 3-5-11 Doshumachi, Chuo-ku, Osaka-shi, Japan Inside Nippon Sheet Glass Co., Ltd. (72) Inventor Harunori Murakami 3-5-11 Dosho-machi, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (72) Inventor Keisuke Tanaka 3-5-11 Doshomachi, Chuo-ku, Osaka City, Osaka Prefecture Inside Nippon Sheet Glass Co., Ltd.
Claims (4)
覆い、該送信部及び受信部をテーパ状の導波部で連結し
たテーパ型の電波暗室であって、前記導波部の床面を大
地等価床で構成し、該導波部の天井面及び側壁面の少な
くとも一部をフェライト電波吸収体で構成したことを特
徴とする電波暗室。1. A tapered anechoic chamber in which the wall surfaces of the transmitter and the receiver are covered with an electromagnetic wave absorber, and the transmitter and the receiver are connected by a tapered waveguide, and the floor of the waveguide is provided. An anechoic chamber characterized in that the surface is constituted by a ground equivalent floor, and at least a part of the ceiling surface and side wall surface of the waveguide is constituted by a ferrite electromagnetic wave absorber.
を大地に対して平坦な構造とし、該受信部及び導波部の
床面をフェライトタイルと導電性フィルムとを組み合わ
せてなる大地等価床で構成したことを特徴とする請求項
１に記載の電波暗室。2. The floor surfaces of the transmitter, the waveguide, and the receiver have a flat structure with respect to the ground, and the floor of the receiver and the waveguide are combined with a ferrite tile and a conductive film. The anechoic chamber according to claim 1, wherein the anechoic chamber comprises a ground equivalent floor.
電波吸収体をフェライトタイルと抵抗損失材料との組み
合わせからなる複合型電波吸収体で構成したことを特徴
とする請求項１又は２に記載の電波暗室。3. The electromagnetic wave absorber disposed on the wall surfaces of the transmitter and the receiver is composed of a composite type electromagnetic wave absorber made of a combination of a ferrite tile and a resistance loss material. The anechoic chamber described.
テナを配置したことを特徴とする請求項１から３のいず
れか１項に記載の電波暗室。4. The anechoic chamber according to claim 1, wherein an independent wideband antenna for transmission is arranged in the transmitting unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27255392A JP3265646B2 (en) | 1992-09-17 | 1992-09-17 | Anechoic chamber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27255392A JP3265646B2 (en) | 1992-09-17 | 1992-09-17 | Anechoic chamber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06104632A true JPH06104632A (en) | 1994-04-15 |
| JP3265646B2 JP3265646B2 (en) | 2002-03-11 |
Family
ID=17515512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27255392A Expired - Lifetime JP3265646B2 (en) | 1992-09-17 | 1992-09-17 | Anechoic chamber |
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| Country | Link |
|---|---|
| JP (1) | JP3265646B2 (en) |
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| JPH0212996A (en) * | 1988-06-30 | 1990-01-17 | Nec Corp | Radio wave absorber |
| JPH0253337A (en) * | 1988-08-18 | 1990-02-22 | Tdk Corp | Anechoic chamber |
| JPH02174199A (en) * | 1988-12-26 | 1990-07-05 | Yokohama Rubber Co Ltd:The | Radio wave anechoic chamber |
| JPH02196500A (en) * | 1989-01-25 | 1990-08-03 | Ngk Insulators Ltd | Cladding tile |
| JPH02228097A (en) * | 1989-02-28 | 1990-09-11 | Toppan Printing Co Ltd | Radio wave anechoic room |
| JPH03124099A (en) * | 1989-10-06 | 1991-05-27 | Toshiba Corp | Radiowave anechoic room |
| JPH0453198A (en) * | 1990-06-15 | 1992-02-20 | Ngk Insulators Ltd | Radio wave anechoic room |
| JPH0462900A (en) * | 1990-06-25 | 1992-02-27 | Tokin Corp | Radio wave dark room |
| JPH04169866A (en) * | 1990-11-02 | 1992-06-17 | Tdk Corp | Radio wave dark room |
| JPH0577782A (en) * | 1991-09-21 | 1993-03-30 | Zeniraito V:Kk | Lighting body |
| JPH0577781A (en) * | 1991-09-19 | 1993-03-30 | Ishikawajima Harima Heavy Ind Co Ltd | Traffic device for tanker |
| JPH0577783U (en) * | 1992-03-23 | 1993-10-22 | 日本板硝子株式会社 | Air conditioning intake / exhaust structure for tapered anechoic chamber |
-
1992
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01135139A (en) * | 1987-11-20 | 1989-05-26 | Tdk Corp | Radio wave dark room |
| JPH0212996A (en) * | 1988-06-30 | 1990-01-17 | Nec Corp | Radio wave absorber |
| JPH0253337A (en) * | 1988-08-18 | 1990-02-22 | Tdk Corp | Anechoic chamber |
| JPH02174199A (en) * | 1988-12-26 | 1990-07-05 | Yokohama Rubber Co Ltd:The | Radio wave anechoic chamber |
| JPH02196500A (en) * | 1989-01-25 | 1990-08-03 | Ngk Insulators Ltd | Cladding tile |
| JPH02228097A (en) * | 1989-02-28 | 1990-09-11 | Toppan Printing Co Ltd | Radio wave anechoic room |
| JPH03124099A (en) * | 1989-10-06 | 1991-05-27 | Toshiba Corp | Radiowave anechoic room |
| JPH0453198A (en) * | 1990-06-15 | 1992-02-20 | Ngk Insulators Ltd | Radio wave anechoic room |
| JPH0462900A (en) * | 1990-06-25 | 1992-02-27 | Tokin Corp | Radio wave dark room |
| JPH04169866A (en) * | 1990-11-02 | 1992-06-17 | Tdk Corp | Radio wave dark room |
| JPH0577781A (en) * | 1991-09-19 | 1993-03-30 | Ishikawajima Harima Heavy Ind Co Ltd | Traffic device for tanker |
| JPH0577782A (en) * | 1991-09-21 | 1993-03-30 | Zeniraito V:Kk | Lighting body |
| JPH0577783U (en) * | 1992-03-23 | 1993-10-22 | 日本板硝子株式会社 | Air conditioning intake / exhaust structure for tapered anechoic chamber |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3265646B2 (en) | 2002-03-11 |
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