JPH07270468A - Electromagnetic wave reflecting desk - Google Patents
Electromagnetic wave reflecting deskInfo
- Publication number
- JPH07270468A JPH07270468A JP6327794A JP6327794A JPH07270468A JP H07270468 A JPH07270468 A JP H07270468A JP 6327794 A JP6327794 A JP 6327794A JP 6327794 A JP6327794 A JP 6327794A JP H07270468 A JPH07270468 A JP H07270468A
- Authority
- JP
- Japan
- Prior art keywords
- desk
- honeycomb
- top plate
- electromagnetic wave
- lower sides
- 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.)
- Pending
Links
Landscapes
- Testing Electric Properties And Detecting Electric Faults (AREA)
- Laminated Bodies (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は電磁波の反射が少なく、
充分な強度を有する机に関し、特に電波暗室や屋外試験
場にて使用される供試体用机に関するものである。BACKGROUND OF THE INVENTION The present invention reduces the reflection of electromagnetic waves,
The present invention relates to a desk having sufficient strength, and particularly to a desk for a specimen used in an anechoic chamber or an outdoor test site.
【０００２】[0002]
【従来の技術】各種の電子機器が広く利用されるように
なり、これらの電子機器が電磁波によって受ける影響お
よび電子機器自身が放射する電磁波が与える影響が問題
となっている。とくに、コンピュータで代表されるよう
なデジタル信号を取り扱う機器が数多く利用されるよう
になり、機器の誤動作等の原因となる電磁波ノイズが大
きな問題となっている。電子機器から発生される電磁波
ノイズ測定（ＥＭＩ測定）は屋外試験場または電波暗室
にて行われており、また、外部から放射される電磁波ノ
イズに対する電子機器の耐性試験（イミュニティ試験）
は電波暗室において行われている。2. Description of the Related Art Various electronic devices have come into widespread use, and the influence of electromagnetic waves on these electronic devices and the influence of electromagnetic waves emitted by the electronic devices themselves pose problems. In particular, many devices such as computers, which handle digital signals, have come to be used, and electromagnetic noise, which causes malfunctions of the devices, has become a serious problem. Electromagnetic noise measurement (EMI measurement) generated from electronic devices is performed in an outdoor test site or an anechoic chamber, and the electronic device resistance test (immunity test) against electromagnetic noise emitted from the outside.
Is performed in an anechoic chamber.
【０００３】イミュニティ試験を行う供試体の電子機器
が机上型ならば供試体用机の上に載置して、電磁波を照
射して試験を行っている。供試体用机は木製又はガラス
繊維強化プラスチックス製のものを使用していたが、数
十ｋｇ以上の供試体重量でも天板がたわまない強度にす
るためには、天板の厚みは約１０ｍｍ以上の厚さのもの
が必要となる。ところが、ＩＥＣ（国際電気標準会議）
等で規定する測定基準では、照射する電磁波の周波数は
２０〜１０００ＭＨｚにわたり、波長が短くなる数百Ｍ
Ｈｚ以上の周波数の電磁波では、天板による表面反射は
無視できない大きさとなる。とくに、表面反射は電磁波
が天板に斜めに入射するときに顕著になり、材料の誘電
率が大きくなるほど、また、厚さが増すほど影響が大き
くなる。If the electronic device of the sample to be subjected to the immunity test is of a desk type, it is placed on a sample table and irradiated with electromagnetic waves to perform the test. The desk for the specimen was made of wood or glass fiber reinforced plastics, but the thickness of the top should be set in order to ensure that the top does not bend even if the weight of the specimen is several tens of kilograms or more. A thickness of about 10 mm or more is required. However, IEC (International Electrotechnical Commission)
According to the measurement standard specified by, etc., the frequency of the electromagnetic wave to be irradiated ranges from 20 to 1000 MHz, and the wavelength becomes several hundreds M
With electromagnetic waves having a frequency of Hz or higher, the surface reflection by the top plate becomes a size that cannot be ignored. In particular, the surface reflection becomes remarkable when the electromagnetic wave is obliquely incident on the top plate, and the influence increases as the dielectric constant of the material increases and the thickness increases.
【０００４】一方、厚みの薄い天板を棒状等の補強用部
材とともに用いて強度を保持することも考えられるが、
使用した補強用部材による電磁波の散乱が無視できない
大きさとなるのでその様なものを使用することはできな
い。また発泡ポリスチレン等の発泡体は、極めて電磁波
の反射が少ないため、供試体を載置する台に使用される
こともあるが、供試体の脚部等によって加えられる集中
荷重に耐えることができず、強度不足のため天板として
使用することができない。On the other hand, it is conceivable to use a thin top plate together with a reinforcing member such as a rod to maintain the strength.
Since the scattering of electromagnetic waves by the reinforcing member used is not negligible, such a thing cannot be used. In addition, since foams such as expanded polystyrene have very little reflection of electromagnetic waves, they are sometimes used for the table on which the sample is placed, but they cannot withstand the concentrated load applied by the legs of the sample. , It cannot be used as a top plate due to lack of strength.
【０００５】また、電波暗室にて電磁波によるイミュニ
ティ試験を行う場合には、供試体用机が電波暗室内の電
磁界分布あるいは電界一様性を乱す原因のひとつである
ことが、不要電波問題対策協議会 平成３年度測定調査
報告書「電波無反射室における垂直面電磁界分布に関す
る調査」、あるいは （社）電子情報通信学会「信学技
報」、ＥＭＣＪ９２−３６（１９９２−０９）「放射電
磁界イミュニティ試験における一方法」等で報告されて
おり、電磁界分布あるいは電界一様性を乱さない供試体
用机が求められている。When performing an immunity test by electromagnetic waves in an anechoic chamber, it is one of the causes that the sample desk disturbs the electromagnetic field distribution or electric field uniformity in the anechoic chamber. Council 1991 Measurement Survey Report “Survey on vertical plane electromagnetic field distribution in non-reflecting room”, IEICE Technical Report, EMCJ92-36 (1992-09) “Radiated electromagnetic field” A method for field immunity test ", etc., and there is a demand for a desk for a specimen that does not disturb the electromagnetic field distribution or the electric field uniformity.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、比較的重量
のある机上型の電子機器の試験が可能で、電波暗室内で
の電磁界分布あるいは電界一様性を乱すことがない電磁
波低反射机を提供することを課題とするものである。DISCLOSURE OF THE INVENTION The present invention is capable of testing a relatively heavy tabletop type electronic device and does not disturb the electromagnetic field distribution or the electric field uniformity in an anechoic chamber and has low electromagnetic wave reflection. The challenge is to provide a desk.
【０００７】[0007]
【課題を解決するための手段】本発明は、机の天板がハ
ニカム状もしくは発泡体からなる絶縁体の上下を厚さ５
ｍｍ以下の絶縁層で積層した積層体から構成されている
電磁波低反射机である。According to the present invention, a top plate of a desk has a thickness of 5 at the top and bottom of an insulator made of honeycomb or foam.
It is an electromagnetic wave low reflection machine composed of a laminate in which insulating layers having a thickness of not more than mm are laminated.
【０００８】また、机の天板と脚部が一体に成形された
ものである電磁波低反射机である。Further, it is an electromagnetic wave low reflection desk in which the top plate and legs of the desk are integrally molded.
【０００９】[0009]
【作用】本発明の電磁波低反射机は、ハニカム構造体も
しくは発泡体からなる絶縁体の両面を厚みの薄い板状体
によって積層したので、強度が大きく天板面からの電磁
波の反射が少ないので、供試体からの放射電磁波あるい
は供試体への電磁波の影響を正確に測定することができ
る。In the electromagnetic wave low reflection machine of the present invention, since both sides of the insulator made of the honeycomb structure or the foam are laminated by the thin plate-like body, the strength is large and the reflection of the electromagnetic wave from the top plate surface is small. It is possible to accurately measure the effect of electromagnetic waves radiated from the test piece or electromagnetic waves on the test piece.
【００１０】[0010]
【実施例】以下に本発明の実施例を示し、本発明を詳細
に説明する。図１に本発明の１実施例を示す。図１
（Ａ）は天板の一部を切り欠いた平面図であり、図１
（Ｂ）は、その一部を切り欠いた断面を示す側面図であ
る。机の天板１は、ハニカム体２と上下の板状体３によ
って構成されている。図に示すように、ハニカムを使用
する場合には、絶縁体であれば各種の材料を使用するこ
とが可能であるが、紙製、あるいは各種の合成樹脂製の
ハニカム構造体を用いることができる。また、発泡体を
用いる場合には、ポリウレタン樹脂、ポリスチレン樹
脂、ポリ塩化ビニル、フェノール樹脂等の発泡体を用い
ることができる。EXAMPLES The present invention will be described in detail below by showing Examples of the present invention. FIG. 1 shows one embodiment of the present invention. Figure 1
FIG. 1A is a plan view in which a part of the top plate is cut away, and FIG.
(B) is a side view showing a cross section with a part thereof cut away. A desk top plate 1 includes a honeycomb body 2 and upper and lower plate-like bodies 3. As shown in the drawing, when a honeycomb is used, various materials can be used as long as they are insulators, but a honeycomb structure made of paper or various synthetic resins can be used. . When a foam is used, a foam such as polyurethane resin, polystyrene resin, polyvinyl chloride, and phenol resin can be used.
【００１１】ハニカムもしくは発泡体の上下に積層する
板状の絶縁体には、ポリ塩化ビニル樹脂、ポリエステル
樹脂からなる板状体あるいは、ポリエステル樹脂、フェ
ノール樹脂、エポキシ樹脂を用いたガラス繊維強化プラ
スチックス等を用いることができる。The plate-like insulators laminated on and under the honeycomb or the foam include plate-like members made of polyvinyl chloride resin or polyester resin, or glass fiber reinforced plastics made of polyester resin, phenol resin or epoxy resin. Etc. can be used.
【００１２】天板に用いる板状体は、５ｍｍ以下である
ことが好ましく、１ｍｍ以下とすることがとくに好まし
く、５ｍｍよりも厚くなると電磁波の反射が大きくな
る。また、ガラス繊維強化プラスチックスであれば、１
ｍｍの厚さであっても、集中化荷重に耐えることがで
き、数１０ｋｇ以上の机上型供試体に使用することがで
きるので、ガラス繊維強化プラスチックスを用いること
が好ましい。また、天板３と脚４は、天板部と脚部が一
体となった金型により一体成形で製作することにより、
天板の裏面等に補強部材を設けることなくさらに強度の
向上した電磁波低反射机を得ることができる。The plate-like body used for the top plate is preferably 5 mm or less, more preferably 1 mm or less, and if it is thicker than 5 mm, the reflection of electromagnetic waves increases. If it is glass fiber reinforced plastics, 1
Even if the thickness is mm, it is preferable to use glass fiber reinforced plastics because it can withstand a concentrated load and can be used for a desktop type test piece of several 10 kg or more. In addition, the top plate 3 and the legs 4 are integrally formed by a mold in which the top plate portion and the leg portions are integrated,
It is possible to obtain an electromagnetic wave low reflection machine having further improved strength without providing a reinforcing member on the back surface of the top plate or the like.
【００１３】実施例１ 厚さ３８ｍｍ、ハニカムの平行な辺の間隔が９ｍｍのク
ラフト紙を使用した密度３１ｋｇ／ｍ3 の紙ハニカム材
（昭和飛行機工業株式会社製 パピコア ９−Ｇ−３
０）の両面に厚さ１ｍｍの板状体が積層され、断面が１
００ｍｍ×１００ｍｍの脚を一体にポリエステル樹脂か
らなる繊維強化プラスチックスを使用して成形した天板
の大きさが縦１０００ｍｍ、横１５００ｍｍであり、高
さ８００ｍｍの電磁波低反射机を製造し、４５ＭＨｚか
ら１．０４５ＧＨｚまでの電磁波反射特性を測定し、そ
の結果を図２の（Ａ）で示す。イミュニティ試験の上限
周波数である１ＧＨｚまで−２０ｄＢ以下という良好な
反射特性を示しており、天板の耐荷重も１００ｋｇ以上
であった。イミュニティ試験用電波暗室に本発明の電磁
波低反射机を配置した場合の電界分布特性は、図３に示
される。図３において、横軸には、測定周波数、縦軸は
電界強度を示しており、イミュニティ試験の国際規格で
あるＩＥＣ ８０１−３ＤＲＡＦＴ−５にて規定されて
いる１６の測定点での２００ＭＨｚから１０００ＭＨｚ
の範囲の測定結果を１６本の曲線で示している。１２以
上の測定点で６ｄＢ以内であり、本発明の電磁波低反射
机が電波暗室内の電界分布を乱さず非常に良好な特性を
有している。Example 1 Paper honeycomb material having a density of 31 kg / m 3 using kraft paper having a thickness of 38 mm and a distance between parallel sides of the honeycomb of 9 mm (Papicore 9-G-3 manufactured by Showa Aircraft Industry Co., Ltd.)
0) is laminated on both sides with a plate-like body having a thickness of 1 mm and has a cross section of 1
The size of the top plate, which is formed by using fiber-reinforced plastics made of polyester resin and integrally formed with legs of 00 mm x 100 mm, is 1000 mm in length and 1500 mm in width, and an electromagnetic low reflection machine with a height of 800 mm is manufactured. The electromagnetic wave reflection characteristics up to 1.045 GHz were measured, and the results are shown in FIG. It showed good reflection characteristics of -20 dB or less up to 1 GHz, which is the upper limit frequency of the immunity test, and the load capacity of the top plate was 100 kg or more. The electric field distribution characteristics when the electromagnetic wave low reflection machine of the present invention is arranged in the anechoic chamber for immunity test are shown in FIG. In FIG. 3, the horizontal axis represents the measurement frequency and the vertical axis represents the electric field strength. 200 MHz to 1000 MHz at 16 measurement points defined by IEC 801-3DRAFT-5, which is an international standard for immunity test.
The measurement results in the range of are shown by 16 curves. It is within 6 dB at 12 or more measurement points, and the electromagnetic wave low reflector of the present invention has very good characteristics without disturbing the electric field distribution in the anechoic chamber.
【００１４】比較例 天板を１０ｍｍ、１５ｍｍ、２０ｍｍの厚さの異なる合
板に変えた点以外は実施例１と同様の机を製造し、実施
例１と同様に測定し、その結果を図２に、それぞれ
（Ｂ）、（Ｃ）、（Ｄ）として示す。Comparative Example A desk similar to that of Example 1 was manufactured except that the top plate was changed to plywood having different thicknesses of 10 mm, 15 mm, and 20 mm, and the desk was measured in the same manner as in Example 1, and the results are shown in FIG. Are shown as (B), (C), and (D), respectively.
【００１５】[0015]
【発明の効果】本発明の電磁波低反射机は、机上型の供
試体のイミュニティ試験において、供試体用机が電波暗
室内の電界分布を乱さないため、試験の再現性の向上に
役立ち試験時間の短縮化が図れる。また机上型の供試体
のＥＭＩ測定においては、供試体から放射されるノイズ
の机による不要な反射がないため、測定値の正確化が図
れる。INDUSTRIAL APPLICABILITY The electromagnetic wave low reflection machine of the present invention is useful for improving the reproducibility of the test in the immunity test of the tabletop type sample, because the sample table does not disturb the electric field distribution in the anechoic chamber. Can be shortened. In addition, in the EMI measurement of the desk-top type test piece, since the noise radiated from the test piece is not unnecessarily reflected by the desk, the measurement value can be made accurate.
【図１】本発明の１実施例を説明する図である。FIG. 1 is a diagram illustrating an embodiment of the present invention.
【図２】本発明の電磁波低反射机の電磁波の反射特性を
説明する図である。FIG. 2 is a diagram illustrating the reflection characteristics of electromagnetic waves of the electromagnetic wave low reflection machine of the present invention.
【図３】本発明の電磁波低反射机を設置した電波暗室内
での電界分布を説明する図である。FIG. 3 is a diagram illustrating an electric field distribution in an anechoic chamber equipped with the electromagnetic wave low reflection machine of the present invention.
１…天板、２…ハニカム体、３…板状体、４…脚 1 ... Top plate, 2 ... Honeycomb body, 3 ... Plate body, 4 ... Leg
Claims (2)
ハニカム状もしくは発泡体からなる絶縁体の上下を厚さ
５ｍｍ以下の絶縁層で積層した積層体から構成されてい
ることを特徴とする電磁波低反射机。1. In an electromagnetic wave low reflection machine, a top plate portion of the desk is composed of a laminated body in which an insulating body having a honeycomb shape or a foamed body is laminated with insulating layers having a thickness of 5 mm or less. An electromagnetic wave low reflection machine.
であることを特徴とする請求項１記載の電磁波低反射
机。2. The low electromagnetic wave reflection machine according to claim 1, wherein the top plate and the legs of the desk are integrally molded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6327794A JPH07270468A (en) | 1994-03-31 | 1994-03-31 | Electromagnetic wave reflecting desk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6327794A JPH07270468A (en) | 1994-03-31 | 1994-03-31 | Electromagnetic wave reflecting desk |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07270468A true JPH07270468A (en) | 1995-10-20 |
Family
ID=13224665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6327794A Pending JPH07270468A (en) | 1994-03-31 | 1994-03-31 | Electromagnetic wave reflecting desk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07270468A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010243260A (en) * | 2009-04-02 | 2010-10-28 | Tdk Corp | Low electromagnetic wave reflection test piece table |
| CN102830293A (en) * | 2012-08-27 | 2012-12-19 | 北京无线电计量测试研究所 | Method and system for quickly calibrating field uniformity of transient electromagnetic field |
-
1994
- 1994-03-31 JP JP6327794A patent/JPH07270468A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010243260A (en) * | 2009-04-02 | 2010-10-28 | Tdk Corp | Low electromagnetic wave reflection test piece table |
| CN102830293A (en) * | 2012-08-27 | 2012-12-19 | 北京无线电计量测试研究所 | Method and system for quickly calibrating field uniformity of transient electromagnetic field |
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