JPH10185973A - Method and device for measuring electromagnetic interference of circuit substrate - Google Patents
Method and device for measuring electromagnetic interference of circuit substrateInfo
- Publication number
- JPH10185973A JPH10185973A JP34626996A JP34626996A JPH10185973A JP H10185973 A JPH10185973 A JP H10185973A JP 34626996 A JP34626996 A JP 34626996A JP 34626996 A JP34626996 A JP 34626996A JP H10185973 A JPH10185973 A JP H10185973A
- Authority
- JP
- Japan
- Prior art keywords
- electric field
- circuit board
- field probe
- electromagnetic interference
- electric
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、印刷配線基板のよ
うな回路基板により生じる電磁障害（ＥＭＩ）を評価す
ることができる回路基板の電磁障害測定方法および測定
装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring electromagnetic interference (EMI) of a circuit board, which can evaluate electromagnetic interference (EMI) caused by a circuit board such as a printed wiring board.
【０００２】[0002]
【従来の技術】一般に、印刷配線基板のような回路基板
を用いる機器では、回路基板の周囲に形成される電磁界
の影響を評価することが要求される。とくに、近年はマ
イクロプロセッサの普及によって回路基板を用いてパル
ス波形であるデジタル信号を伝送する機会が増加してお
り、しかもクロック周波数が年々上昇しているので、回
路基板からの電磁輻射が増加する傾向にある。あるいは
また、電源装置としてスイッチング電源やインバータ回
路が多用されており、この種の回路装置によっても電磁
輻射が増加する傾向にある。2. Description of the Related Art In general, in an apparatus using a circuit board such as a printed wiring board, it is required to evaluate the influence of an electromagnetic field formed around the circuit board. In particular, in recent years, with the spread of microprocessors, the opportunity to transmit a digital signal having a pulse waveform using a circuit board has been increasing, and the clock frequency has been increasing year by year, so that electromagnetic radiation from the circuit board has increased. There is a tendency. Alternatively, a switching power supply or an inverter circuit is frequently used as a power supply device, and this type of circuit device also tends to increase electromagnetic radiation.
【０００３】このような電磁輻射つまり電磁障害を評価
する際には、回路基板に対してある程度距離の離れた位
置（たとえば３ｍ）での電磁障害の程度を評価すること
が重要である。しかしながら、回路基板から離れた位置
の電磁障害の程度を直接測定しようとすれば大型の電波
暗室が必要になる。そこで、回路基板から比較的近い場
所で電磁波を測定し、測定値に基づいて回路基板から離
れた場所での電磁障害を予測することが考えられてい
る。When evaluating such electromagnetic radiation, that is, electromagnetic interference, it is important to evaluate the degree of the electromagnetic interference at a position (for example, 3 m) apart from the circuit board by a certain distance. However, in order to directly measure the degree of electromagnetic interference at a position distant from the circuit board, a large anechoic chamber is required. Therefore, it has been considered to measure electromagnetic waves at a location relatively close to the circuit board, and to predict electromagnetic interference at a location distant from the circuit board based on the measured values.
【０００４】この種の測定には、図１０および図１１に
示すように、回路基板１の周囲に形成される磁界の強さ
を測定する磁界プローブ８を用いるとともに、磁界プロ
ーブ８を回路基板１に対して走査する技術が考えられて
いる。つまり、測定対象となる回路基板１を取り付ける
基板設置台９ａと、磁界プローブ８を回路基板１に対し
て縦横に走査するプローブ走査装置９ｂとを備える測定
具９を用い、回路基板１の全体を磁界プローブ８で走査
するのである。磁界プローブ８の出力は微弱であるか
ら、磁気プローブ８の出力はプリアンプ６により増幅さ
れる。このようにして得られた測定値は、スペクトルア
ナライザ３により周波数分析され、スペクトルアナライ
ザ３により抽出された周波数成分と他の既知情報とを用
いて回路基板１から遠方の所望位置の電磁障害を予測す
るのである。この予測にはコンピュータ４のような演算
装置を用いる。For this type of measurement, as shown in FIGS. 10 and 11, a magnetic field probe 8 for measuring the intensity of a magnetic field formed around the circuit board 1 is used, and the magnetic field probe 8 is connected to the circuit board 1 as shown in FIG. A technology for scanning with respect to is considered. In other words, the entire circuit board 1 is used by using a measuring tool 9 including a board mounting table 9a for mounting the circuit board 1 to be measured and a probe scanning device 9b for scanning the magnetic field probe 8 vertically and horizontally with respect to the circuit board 1. The scanning is performed by the magnetic field probe 8. Since the output of the magnetic field probe 8 is weak, the output of the magnetic probe 8 is amplified by the preamplifier 6. The measured value obtained in this manner is subjected to frequency analysis by the spectrum analyzer 3, and the electromagnetic interference at a desired position far from the circuit board 1 is predicted using the frequency components extracted by the spectrum analyzer 3 and other known information. You do it. An arithmetic device such as the computer 4 is used for this prediction.
【０００５】[0005]
【発明が解決しようとする課題】上述した技術を採用す
れば、回路基板１上の電磁波の強度分布を知ることがで
きるが、実際には回路基板１の各部を流れる電流は時間
経過に伴って変化しており、当然ながら磁界プローブ８
によって回路基板１を走査している間にも電流は変化す
るから、上述のようにして得られた測定値を用いて回路
基板１から遠方の電磁障害を予測したとしても、回路基
板１全体の総合的な電磁障害の程度を予測するのは難し
いものである。また、磁界プローブ８を走査しなければ
ならないから、装置が複雑な構成になるとともに、装置
が大型化するという問題もある。By employing the above-described technique, the intensity distribution of the electromagnetic wave on the circuit board 1 can be known. However, the current flowing through each part of the circuit board 1 actually changes with time. The magnetic field probe 8
Therefore, the current changes while the circuit board 1 is being scanned, so that even if the electromagnetic interference far from the circuit board 1 is predicted using the measured values obtained as described above, It is difficult to predict the overall magnitude of electromagnetic interference. Further, since the magnetic field probe 8 must be scanned, there is a problem that the device becomes complicated and the device becomes large.
【０００６】本発明は上記事由に鑑みて為されたもので
あり、その目的は、回路基板の近傍での測定値に基づい
て回路基板から遠方の任意の位置での電磁障害の程度を
予測できるようにし、しかも回路基板全体の総合的な電
磁障害の程度を精度よく予測できるようにした回路基板
の電磁障害測定方法および測定装置を提供することにあ
る。The present invention has been made in view of the above circumstances, and has as its object to predict the degree of electromagnetic interference at an arbitrary position distant from a circuit board based on measured values near the circuit board. Accordingly, it is an object of the present invention to provide a method and an apparatus for measuring an electromagnetic interference of a circuit board, wherein the degree of the total electromagnetic interference of the entire circuit board can be accurately predicted.
【０００７】[0007]
【課題を解決するための手段】請求項１の発明は、電磁
障害の測定対象となる回路基板の近傍に配置された電界
プローブを用いて回路基板の近傍に形成される電界の強
度を測定し、測定された電界の強度に電気双極子による
モデルを適用し回路基板に対して電界プローブよりも遠
方となる任意の位置の電磁障害を予測演算するものであ
る。この方法によれば、回路基板の近傍に配置した電界
プローブを用いるとともに電気双極子によるモデルを適
用して遠方の電磁障害を予測するのであり、大型の設備
が不要になるという利点があり、しかも後述するよう
に、電界の測定値を適用すると磁界の測定値を用いる場
合に比較して、回路基板の近傍から遠方まで適用可能な
電気双極子によるモデルを用いることが可能になり、結
果として精度のよい予測が可能になる。According to a first aspect of the present invention, the intensity of an electric field formed near a circuit board is measured using an electric field probe arranged near a circuit board to be measured for electromagnetic interference. And applying an electric dipole model to the measured electric field strength to predict and calculate an electromagnetic interference at an arbitrary position farther from the circuit board than the electric field probe. According to this method, an electric field probe arranged near the circuit board is used, and at the same time, a model based on an electric dipole is used to predict a distant electromagnetic interference. As will be described later, applying the measured value of the electric field makes it possible to use a model based on electric dipoles that can be applied from near to far from the circuit board, compared to using the measured value of the magnetic field. Good prediction is possible.
【０００８】請求項２の発明は、請求項１の発明におい
て、電界プローブを無指向性としたものである。この方
法では、測定対象となる回路基板の方向性の影響を受け
にくく、誤差の発生が少なくなって、精度が一層高くな
るのである。請求項３の発明は、請求項１または請求項
２の発明において、電界プローブを回路基板に対して定
位置に固定したものである。電界プローブを用いる場合
には、磁気プローブのような走査装置が不要であるか
ら、電界プローブを定位置に固定して得た測定値に基づ
いて遠方での電磁障害を予測することができる。しかも
電界プローブを走査することなく定点で電界を測定する
から、短時間で測定することができる。According to a second aspect of the present invention, in the first aspect, the electric field probe is made non-directional. According to this method, the influence of the directionality of the circuit board to be measured is hardly affected, errors are reduced, and the accuracy is further improved. According to a third aspect of the present invention, in the first or second aspect, the electric field probe is fixed at a fixed position with respect to the circuit board. When an electric field probe is used, since a scanning device such as a magnetic probe is not required, it is possible to predict electromagnetic interference at a distant place based on a measurement value obtained by fixing the electric field probe at a fixed position. Moreover, since the electric field is measured at a fixed point without scanning the electric field probe, the measurement can be performed in a short time.
【０００９】請求項４の発明は、請求項３の発明におい
て、回路基板の中心を通り回路基板の表面に直交する線
上に電界プローブを配置したものである。この方法は、
各種回路基板に対してほぼ同じ条件を設定することにな
り、結果的に再現性が高くなるのである。請求項５の発
明は、請求項４の発明において、電界プローブにより検
出される電界の強度を、電気双極子の中心と電界プロー
ブの中心と回路基板の中心とを含む平面内において電気
双極子と電界プローブの中心とを結ぶ直線に直交する成
分とみなし、回路基板に対して電界プローブよりも遠方
となる任意の位置の電磁障害を予測演算するものであ
る。この方法によれば、電気双極子によるモデルと予測
値との関係が明確に規定されることになり、求めた予測
値の意味付けによって予測誤差の程度も明確になる。According to a fourth aspect of the present invention, in the third aspect, the electric field probe is arranged on a line passing through the center of the circuit board and orthogonal to the surface of the circuit board. This method
Approximately the same conditions are set for various circuit boards, resulting in higher reproducibility. According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the electric field intensity detected by the electric field probe is set to be equal to the electric dipole in a plane including the center of the electric dipole, the center of the electric field probe, and the center of the circuit board. The component is regarded as a component orthogonal to a straight line connecting to the center of the electric field probe, and predicts and calculates electromagnetic interference at an arbitrary position farther from the circuit board than the electric field probe. According to this method, the relationship between the model based on the electric dipole and the predicted value is clearly defined, and the significance of the obtained predicted value also clarifies the degree of the prediction error.
【００１０】請求項６の発明は、電磁障害の測定対象と
なる回路基板の近傍の定位置に固定された電界プローブ
と、電界プローブにより測定された回路基板の近傍の電
界の強度に対して電気双極子によるモデルを適用し回路
基板に対して電界プローブよりも遠方となる任意の位置
の電磁障害を予測演算する演算手段とを備えるものであ
る。この構成によれば、回路基板の近傍に配置した電界
プローブを用いるとともに電気双極子によるモデルを適
用して遠方の電磁障害を予測するから、大型の設備が不
要になり、また、電気双極子によるモデルを用いること
によって回路基板の近傍の電界の測定により回路基板の
遠方まで精度のよい予測が可能になるのである。According to a sixth aspect of the present invention, there is provided an electric field probe fixed at a fixed position in the vicinity of a circuit board to be measured for electromagnetic interference, and an electric field probe in the vicinity of the circuit board measured by the electric field probe. A calculating means for predicting and calculating an electromagnetic interference at an arbitrary position farther than the electric field probe with respect to the circuit board by applying a dipole model. According to this configuration, a large-scale facility is unnecessary because the electric field probe placed near the circuit board is used and a model based on the electric dipole is used to predict a distant electromagnetic interference. By using the model, it is possible to accurately predict the distance to the circuit board by measuring the electric field near the circuit board.
【００１１】[0011]
【発明の実施の形態】本実施形態では回路基板１の周囲
の電磁障害を評価するための測定値を得る装置として、
図１に示すように、回路基板１に対して定位置に固定さ
れた電界プローブ２と、電界プローブ２の出力を周波数
分析するスペクトルアナライザ３と、スペクトルアナラ
イザ３で求めた各周波数ごとのレベルに基づいて回路基
板１から離れた任意の位置での電磁障害を予測する演算
装置としてのコンピュータ４とを用いている。電界プロ
ーブ２は無指向性のものを用いており、回路基板１の中
心を通り回路基板１の表面に直交する直線上の定位置に
固定台５によって固定されている。この距離については
後述する。また、電界プローブ２の出力は微小であるか
ら、プリアンプ６を通して増幅した後にスペクトルアナ
ライザ３に入力する。ちなみに、スペクトルアナライザ
３とコンピュータ４との間の接続はとくに制限されるも
のではないが、データ伝送速度が比較的速く、しかも測
定器用のインタフェースとして普及しているＧＰＩＢ規
格のケーブル７を用いている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, an apparatus for obtaining a measured value for evaluating electromagnetic interference around a circuit board 1 will be described.
As shown in FIG. 1, an electric field probe 2 fixed at a fixed position with respect to a circuit board 1, a spectrum analyzer 3 for analyzing the output of the electric field probe 2 and a level for each frequency obtained by the spectrum analyzer 3 A computer 4 is used as an arithmetic device that predicts electromagnetic interference at an arbitrary position distant from the circuit board 1 based on the information. The electric field probe 2 is of a non-directional type, and is fixed by a fixing base 5 at a fixed position on a straight line passing through the center of the circuit board 1 and orthogonal to the surface of the circuit board 1. This distance will be described later. Further, since the output of the electric field probe 2 is very small, it is input to the spectrum analyzer 3 after being amplified through the preamplifier 6. Incidentally, although the connection between the spectrum analyzer 3 and the computer 4 is not particularly limited, the GPIB standard cable 7, which has a relatively high data transmission speed and is widely used as an interface for measuring instruments, is used. .
【００１２】ところで、本発明者らは、従来用いられて
いた磁界プローブに代えて電気プローブ２を用いるため
に、図２（ａ）のようなループ状（ここでは、５ｃｍ×
８ｃｍの矩形状とし、一方の長辺の中央部から高周波電
流を供給している）や図２（ｂ）のような平行２線状
（ここでは、各１５ｃｍとして一端部間に５０Ωのイン
ピーダンス要素１４を接続してある。）などの簡単な回
路パターンを回路基板１である印刷配線基板に形成し、
表面電流プローブ（トロイダルコアを半割にしたものに
巻線を設けたものをセンサとして巻線への誘起電圧を測
定するもの）を用いてコモンモード電流とノーマルモー
ド電流とを測定した。この実験では３０ＭＨｚ〜１ＧＨ
ｚの電流を回路パターンに流し、回路基板１から３ｍ離
れた場所での輻射レベルを予測することを考えた。この
ような実験によって、輻射の発生機構として電気双極子
を用いたモデルを想定すると実測値に対して、よい予測
値を与えることができるという知見を得ることができ
た。すなわち、電磁波の放射機構として電気双極子のモ
ーメントの時間変化によるモデルを採用し、回路基板１
に対してこのモデルを適用した場合によい予測値を得る
ことができることがわかった。By the way, the present inventors use a loop-shaped (5 cm × 5 cm here) as shown in FIG. 2A in order to use the electric probe 2 instead of the magnetic field probe conventionally used.
An 8 cm rectangular shape, and a high-frequency current is supplied from the center of one of the long sides) or a parallel two-line shape as shown in FIG. 14 is connected to the printed circuit board, which is the circuit board 1,
A common mode current and a normal mode current were measured using a surface current probe (a device in which a winding was provided on a half of a toroidal core and a winding was used as a sensor to measure an induced voltage to the winding). In this experiment, 30MHz ~ 1GH
It is considered that a current of z is caused to flow through the circuit pattern to predict a radiation level at a position 3 m away from the circuit board 1. Through such experiments, it was possible to obtain a finding that a good prediction value can be given to an actually measured value when a model using an electric dipole as a radiation generation mechanism is assumed. That is, a model based on the time change of the moment of the electric dipole is adopted as the radiation mechanism of the electromagnetic wave.
It was found that a good prediction value could be obtained when this model was applied to.
【００１３】しかしながら、上述のような電流の測定に
よって遠方（たとえば、回路基板１から３ｍの位置）の
輻射レベルを予測しようとすると、回路基板１に形成さ
れる回路パターンによっては予測が難しい場合がある。
たとえば、両面基板であって一面に回路パターンが形成
され他面は回路パターンを形成していない銅箔で覆われ
ている場合や、回路パターンの周囲がアースパターンで
囲まれているような場合には、電気双極子の簡単なモデ
ルでは予測が難しいことがわかった。However, when trying to predict the radiation level in a distant place (for example, at a position 3 m from the circuit board 1) by measuring the current as described above, it is sometimes difficult to predict the radiation level depending on the circuit pattern formed on the circuit board 1. is there.
For example, when the circuit pattern is formed on one side and the other side is covered with copper foil that does not form a circuit pattern, or when the circuit pattern is surrounded by a ground pattern on a double-sided board Found that a simple model of the electric dipole was difficult to predict.
【００１４】たとえば、図２（ａ）や図３に示すような
５ｃｍ×８ｃｍの矩形ループ状の回路パターン１１を一
面に形成し、他面のほぼ全面に銅箔の接地導体１２を設
けた回路基板１を用い、３ｍの距離での予測値と実測値
とを比較したところ、図４に示すような結果が得られ
た。予測値は最大値（一点鎖線）と最小値（破線）とを
求めた。また、図の実線は実測値を示す。図４によりわ
かるように、上述した電流測定からの予測では、実測値
が予測値の最大値と最小値との間に収まらない箇所があ
り、図３のような比較的簡単な回路であっても予測値が
実測値に一致しないことがあるから、実際に電子部品を
実装した複雑な回路パターンのものを予測するのは困難
であると言える。For example, a circuit in which a rectangular loop-shaped circuit pattern 11 of 5 cm × 8 cm as shown in FIG. 2A or 3 is formed on one surface and a ground conductor 12 of copper foil is provided on almost the entire other surface. When the predicted value and the actually measured value at a distance of 3 m were compared using the substrate 1, the result as shown in FIG. 4 was obtained. For the predicted value, a maximum value (dashed line) and a minimum value (dashed line) were obtained. Further, the solid line in the figure shows the actually measured value. As can be seen from FIG. 4, in the prediction based on the current measurement described above, there are places where the actual measurement value does not fall between the maximum value and the minimum value of the predicted value, and a relatively simple circuit as shown in FIG. It can be said that it is difficult to predict a complicated circuit pattern on which electronic components are actually mounted, because the predicted value may not coincide with the actually measured value.
【００１５】そこで、本発明者らは、電界プローブ２を
用いて回路基板１の近傍での電界を測定すれば、電気双
極子モデルを適用して高い精度で予測値を与えることが
できるという仮説を立て、これを検証するための実験を
行なった。電界プローブ２としては無指向性のもの（米
ＥＭＣＯ社製：近傍電界プローブ、モデル７４０５−９
０４、３．６ｃｍボール型）を用い、回路基板１からの
距離（電気双極子の中心からの距離）を３段階（５ｃ
ｍ、１０ｃｍ、２０ｃｍ）に変え、他の条件は同じにし
て電界を測定し、その結果から予測値を算出した。ま
た、回路パターン１１は図２（ａ）、図３に示すものと
同じものを用いた。その結果を図５に示す。図５から明
らかなように、図４に示した予測値に比較するとかなり
よい予測値が得られていることがわかる。とくに、１０
ｃｍ（二点鎖線）の距離に設定した場合に実測値（実
線）との一致の程度が高いことがわかる。ここに、図５
の一点鎖線は５ｃｍ、破線は２０ｃｍの場合を示す。Therefore, the present inventors hypothesized that if an electric field near the circuit board 1 is measured using the electric field probe 2, a predicted value can be given with high accuracy by applying an electric dipole model. And an experiment was conducted to verify this. As the electric field probe 2, a non-directional probe (manufactured by EMCO, USA: proximity electric field probe, model 7405-9)
04, 3.6 cm ball type) and the distance from the circuit board 1 (the distance from the center of the electric dipole) in three steps (5c
m, 10 cm, 20 cm), the electric field was measured under the same other conditions, and a predicted value was calculated from the result. The same circuit pattern 11 as that shown in FIGS. 2A and 3 was used. The result is shown in FIG. As is clear from FIG. 5, it can be seen that a considerably better predicted value is obtained as compared with the predicted value shown in FIG. Especially 10
It can be seen that the degree of coincidence with the measured value (solid line) is high when the distance is set to cm (two-dot chain line). Here, FIG.
The dashed line indicates the case of 5 cm, and the broken line indicates the case of 20 cm.
【００１６】また、図２（ｂ）の回路パターン１１につ
いて同様の測定を行ない、予測値を求めたところ図８の
ような結果が得られた。図８においても実線は実測値、
二点鎖線は１０ｃｍ、一点鎖線は５ｃｍ、破線は２０ｃ
ｍの測定値に基づく予測値を示す。図８によれば、この
回路パターン１１でもよい精度で予測することができ、
しかも１０ｃｍの距離で電界を測定したときにもっとも
よい予測値が得られていることがわかる。Further, the same measurement was performed for the circuit pattern 11 in FIG. 2B, and a predicted value was obtained. The result shown in FIG. 8 was obtained. In FIG. 8 as well, the solid line is the measured value,
The two-dot chain line is 10 cm, the one-dot chain line is 5 cm, and the dashed line is 20 c
The predicted value based on the measured value of m is shown. According to FIG. 8, the circuit pattern 11 can be predicted with good accuracy.
Moreover, it can be seen that the best predicted value was obtained when the electric field was measured at a distance of 10 cm.
【００１７】予測値は図６のような球座標を考え、電気
双極子１３の中心を原点、電流の向きをＺ軸方向の正の
向き、電気双極子１３の電流振幅をＩ、電気双極子１３
の長さをdlとして求めた。いま、電気双極子１３の電流
が周波数ｆ（＝ｃ／λ0 ：ｃは光速、λ0 は波長）の正
弦波状に変化するものとして、誘電率および透磁率が一
様とみなせる空気中で測定し、波数をβ0 ＝２π／
λ0 、真空におけるインピーダンスをη0 ＝（μ0 ／ε
0 ）1/2 （μ0 は真空の透磁率、ε0 は真空の誘電率）
とおけば、上述の球座標空間における点（ｒ，θ，φ）
の電界と磁界とは数１のように表されることが知られて
いる。ただし、ｃは光速である。Considering the spherical coordinates as shown in FIG. 6, the predicted value is the origin at the center of the electric dipole 13, the direction of the current is positive in the Z-axis direction, the current amplitude of the electric dipole 13 is I, the electric dipole is 13
Was obtained as dl. Now, assuming that the current of the electric dipole 13 changes sinusoidally at a frequency f (= c / λ 0 : c is the speed of light and λ 0 is the wavelength), the measurement is performed in air where the dielectric constant and the magnetic permeability can be regarded as uniform. And the wave number is β 0 = 2π /
λ 0 , the impedance in a vacuum is η 0 = (μ 0 / ε
0 ) 1/2 (μ 0 is the magnetic permeability of vacuum, ε 0 is the dielectric constant of vacuum)
Then, the point (r, θ, φ) in the above spherical coordinate space
It is known that the electric field and the magnetic field are expressed as Equation 1. Here, c is the speed of light.
【００１８】[0018]
【数１】 (Equation 1)
【００１９】数１において電界強度、磁界強度、電流の
上の山形記号（＾）はベクトルを意味する。また、数１
に示した成分以外の電界および磁界はすべて０になる。
ここで、数１の３つの式のうち最下段である第３式は磁
界の強度を表しており、本発明では採用しないのである
から、上の２式のいずれかを予測式として用いることに
なる。しかしながら、第２式により表される電界強度の
ｒ方向成分については、距離ｒに関する項が１／ｒ2 と
１／ｒ3 としかなく、遠方ではこれらの成分はほとんど
寄与しなくなるから、採用することができない。つま
り、回路基板１から遠方での電磁波の予測には数１の最
上段である第１式を用いて電界強度のθ成分を測定する
ことになる。第１式によれば、回路基板１から近距離の
範囲では１／ｒ3 の成分が支配的であり、回路基板１か
ら遠方になると１／ｒの成分が支配的になる。In equation (1), a chevron (＾) above the electric field strength, magnetic field strength, and current means a vector. Also, Equation 1
All electric and magnetic fields other than the components shown in FIG.
Here, the lowermost expression of the three expressions of Expression 1 represents the magnetic field strength and is not adopted in the present invention. Therefore, either of the above two expressions is used as a prediction expression. Become. However, the r-direction component of the electric field strength represented by the second equation is employed because the term related to the distance r is only 1 / r 2 and 1 / r 3, and these components hardly contribute at a long distance. Can not do. That is, in predicting an electromagnetic wave far from the circuit board 1, the θ component of the electric field strength is measured by using the first equation, which is the uppermost stage of the equation (1). According to the first equation, the 1 / r 3 component is dominant in a short distance range from the circuit board 1, and the 1 / r component becomes dominant in a distance from the circuit board 1.
【００２０】そこで、回路基板１の近くで電界プローブ
２により電界強度のθ方向成分を測定し、既知であるη
0 、β0 、ｒを数１の第１式に代入すれば、電気双極子
モーメント（大きさはＩdl cosωｔ／ω）に対応したＩ
dl sinθを求めることができる。Ｉdl sinθを求めた後
に、回路基板１から遠方に位置する所望の距離ｒを数１
の第１式に与えると、遠方での電界強度を求めることが
できる。Therefore, the component of the electric field intensity in the θ direction is measured by the electric field probe 2 near the circuit board 1, and the known η
By substituting 0 , β 0 , and r into the first equation of Equation 1, I corresponding to the electric dipole moment (the magnitude is Idl cosωt / ω)
dl sinθ can be obtained. After obtaining Idl sin θ, the desired distance r located far from the circuit board 1 is expressed by the following equation (1).
Given by the first equation, the electric field strength at a distant place can be obtained.
【００２１】ところで、上述したモデルのように電気双
極子１３の電流の向きをＺ軸方向とすれば、電界強度の
θ方向成分はＸＹ平面（θ＝π／２）上で最大になる。
また、Ｚ軸（θ＝０）上では最小になる。つまり、他の
条件が同じであれば sinθに応じて大きさが変化する。
このことから、電気双極子１３に対してＺ軸方向に電界
プローブ２を配置しても目的を達成できないことがわか
る。ただし、Ｘ軸方向、Ｙ軸方向についてはとくに制限
は生じない。以上のことから、簡単な回路パターン１１
については予測値と実測値とがよく一致するという結論
を得ることができた（３０〜７００ＭＨｚで７ｄＢ以
内）。Assuming that the direction of the current of the electric dipole 13 is the Z-axis direction as in the above-described model, the component of the electric field intensity in the θ direction becomes maximum on the XY plane (θ = π / 2).
Further, it becomes minimum on the Z axis (θ = 0). That is, if other conditions are the same, the size changes according to sin θ.
This indicates that the object cannot be achieved even if the electric field probe 2 is arranged in the Z-axis direction with respect to the electric dipole 13. However, there are no particular restrictions on the X-axis direction and the Y-axis direction. From the above, the simple circuit pattern 11
It was possible to obtain a conclusion that the predicted value and the actually measured value were well matched (within 7 dB at 30 to 700 MHz).
【００２２】上述のモデルは簡単な回路パターン１１に
対して設定したが、実際に電子部品を実装した回路で
は、図７のように電流の大きさや長さが異なるととも
に、電流の向きが異なる多数の電気双極子１３が生じる
と考えられる。ただし、電気双極子１３は回路基板１に
沿って形成されるから、すべての電気双極子１３により
形成される電界についてθ方向成分に相当する電界強度
を測定しようとすれば、電界プルーブ２は回路基板１の
平面内ではない場所に配置することが必要である。そこ
で、回路基板１をＹＺ平面とするときに、回路基板１へ
の電子部品の実装面側で回路基板１からＸ方向に離れた
位置に電界プローブ２を配置する。このように電界プル
ーブ２を配置することによって、どの電気双極子１３に
ついてもθ方向成分に相当する電界強度を測定すること
が可能になる。このような考えに基づいてマイクロプロ
セッサを実装した制御用の回路基板１やネットワーク構
築用の回路を実装した回路基板１についても同様の測定
を行ない、予測値を求めたところ、図９に示すように、
よい予測値を得ることができた。とくに１００ＭＨｚ〜
１ＧＨｚの範囲ではよい予測値を得ることができた。図
９において実線は実測値、二点鎖線は１０ｃｍ、一点鎖
線は５ｃｍ、破線は２０ｃｍでの測定に基づいた予測値
を示す。各電気双極子１３の周囲の電界強度のθ方向成
分を考え、各電気双極子１３はＹ軸方向とＺ軸方向との
いずれかを向いているものとしたときに、数２のような
関係を得ることができる。Although the above-described model is set for a simple circuit pattern 11, in a circuit in which electronic components are actually mounted, as shown in FIG. Is considered to occur. However, since the electric dipole 13 is formed along the circuit board 1, if the electric field strength corresponding to the θ-direction component is to be measured for the electric field formed by all the electric dipoles 13, the electric field probe 2 will It is necessary to arrange it in a place other than the plane of the substrate 1. Therefore, when the circuit board 1 is set to the YZ plane, the electric field probe 2 is arranged at a position away from the circuit board 1 in the X direction on the mounting surface side of the electronic component on the circuit board 1. By arranging the electric field probe 2 in this manner, it is possible to measure the electric field intensity corresponding to the θ-direction component for any electric dipole 13. Based on such an idea, the same measurement was performed on the control circuit board 1 on which the microprocessor was mounted and the circuit board 1 on which the network building circuit was mounted, and the predicted value was obtained. As shown in FIG. To
Good predictions could be obtained. Especially 100MHz ~
Good prediction values could be obtained in the range of 1 GHz. In FIG. 9, the solid line indicates the actual measurement value, the two-dot chain line indicates the predicted value based on the measurement at 10 cm, the one-dot chain line indicates the predicted value based on the measurement at 5 cm, and the dashed line indicates the predicted value. Considering the θ-direction component of the electric field strength around each electric dipole 13, when each electric dipole 13 is oriented in either the Y-axis direction or the Z-axis direction, a relationship such as Expression 2 is obtained. Can be obtained.
【００２３】[0023]
【数２】 (Equation 2)
【００２４】数２においてＭａｘ（Ａ，Ｂ）は、ＡとＢ
との大きいほうという意味である。数２によれば、Ｙ軸
方向とＺ軸方向との各電気双極子１３の電界強度のθ方
向成分の総和の平方和の平行根は、総和のうちの大きい
ほうの値の２の平方根倍以下になるのであるから、これ
をデシベルに換算すれば、誤差は高々３ｄＢ（≒１０lo
g（２）1/2 ）であると言える。In Equation 2, Max (A, B) is A and B
Means larger. According to Equation 2, the parallel root of the sum of squares of the sum of the components in the θ direction of the electric field strength of the electric dipoles 13 in the Y-axis direction and the Z-axis direction is the square root of 2 which is the larger value of the sum. When converted to decibels, the error is at most 3 dB (ｄ10 lo).
g (2) 1/2 ).
【００２５】以上の結果、電子部品を実装した回路基板
１においても、回路基板１とは異なる面内で回路基板１
の近傍に配置した電界プローブ２を用いて電界強度を測
定することにより測定値を数１の第１式に代入して未知
数を決定し、回路基板１の遠方における電界強度を予測
することができるのである。また、この予測値は実測値
によく一致するから、電磁障害のレベルの評価に有用で
ある。As a result, the circuit board 1 on which the electronic components are mounted can be mounted on a different plane from the circuit board 1.
The electric field strength is measured by using the electric field probe 2 arranged in the vicinity of, and the unknown value is determined by substituting the measured value into the first equation of the formula (1), so that the electric field strength in the distance of the circuit board 1 can be predicted. It is. In addition, since the predicted value agrees well with the actually measured value, it is useful for evaluating the level of electromagnetic interference.
【００２６】[0026]
【発明の効果】請求項１の発明は、電磁障害の測定対象
となる回路基板の近傍に配置された電界プローブを用い
て回路基板の近傍に形成される電界の強度を測定し、測
定された電界の強度に電気双極子によるモデルを適用し
回路基板に対して電界プローブよりも遠方となる任意の
位置の電磁障害を予測演算するものであり、回路基板の
近傍に配置した電界プローブを用いるとともに電気双極
子によるモデルを適用して遠方の電磁障害を予測するの
で、大型の設備が不要になるという利点があり、しか
も、電界の測定値を適用すると磁界の測定値を用いる場
合に比較して、回路基板の近傍から遠方まで適用可能な
電気双極子によるモデルを用いることが可能になるか
ら、精度のよい予測が可能になるという利点がある。According to the first aspect of the present invention, the strength of the electric field formed near the circuit board is measured using an electric field probe arranged near the circuit board to be measured for electromagnetic interference, and the measured electric field strength is measured. It applies an electric dipole model to the strength of the electric field and predicts and calculates electromagnetic interference at an arbitrary position farther than the electric field probe with respect to the circuit board. The use of electric dipole models to predict distant electromagnetic interference has the advantage of eliminating the need for large-scale equipment.Moreover, applying measured values of the electric field is more effective than using measured values of the magnetic field. Since it is possible to use a model using an electric dipole applicable from near to far from the circuit board, there is an advantage that accurate prediction can be performed.
【００２７】請求項２の発明のように、電界プローブを
無指向性としたものでは、測定対象となる回路基板の方
向性の影響を受けにくく、誤差の発生が少なくなって、
精度が一層高くなるという利点がある。請求項３の発明
のように、電界プローブを回路基板に対して定位置に固
定したものでは、磁気プローブのような走査装置が不要
であるから、電界プローブを定位置に固定して得た測定
値に基づいて遠方での電磁障害を予測することができる
という利点がある。しかも電界プローブを走査すること
なく定点で電界を測定するから、短時間で測定すること
ができるという利点がある。According to the second aspect of the present invention, when the electric field probe is omnidirectional, it is hardly affected by the directionality of the circuit board to be measured, and the occurrence of errors is reduced.
There is an advantage that the accuracy is further improved. In the case where the electric field probe is fixed at a fixed position with respect to the circuit board as in the invention of claim 3, since a scanning device such as a magnetic probe is not required, the measurement obtained by fixing the electric field probe at a fixed position is not necessary. An advantage is that electromagnetic interference at a distance can be predicted based on the value. Moreover, since the electric field is measured at a fixed point without scanning the electric field probe, there is an advantage that the measurement can be performed in a short time.
【００２８】請求項４の発明のように、回路基板の中心
を通り回路基板の表面に直交する線上に電界プローブを
配置したものでは、各種回路基板に対してほぼ同じ条件
を設定することになり、結果的に再現性が高くなるとい
う利点がある。請求項５の発明のように、電界プローブ
により検出される電界の強度を、電気双極子の中心と電
界プローブの中心と回路基板の中心とを含む平面内にお
いて電気双極子と電界プローブの中心とを結ぶ直線に直
交する成分とみなし、回路基板に対して電界プローブよ
りも遠方となる任意の位置の電磁障害を予測演算するも
のでは、電気双極子によるモデルと予測値との関係が明
確に規定されることになり、求めた予測値の意味付けに
よって予測誤差の程度も明確になるという利点がある。In the case where the electric field probe is arranged on a line passing through the center of the circuit board and perpendicular to the surface of the circuit board, almost the same conditions are set for various circuit boards. As a result, there is an advantage that reproducibility is improved. According to the fifth aspect of the present invention, the intensity of the electric field detected by the electric field probe is adjusted by the electric dipole and the center of the electric field probe in a plane including the center of the electric dipole, the center of the electric field probe, and the center of the circuit board. For a component that predicts electromagnetic interference at an arbitrary position that is farther than the electric field probe with respect to the circuit board, assuming that the component is orthogonal to the straight line connecting the lines, the relationship between the model and the predicted value by the electric dipole is clearly specified. Therefore, there is an advantage that the degree of the prediction error becomes clear according to the meaning of the obtained predicted value.
【００２９】請求項６の発明は、電磁障害の測定対象と
なる回路基板の近傍の定位置に固定された電界プローブ
と、電界プローブにより測定された回路基板の近傍の電
界の強度に対して電気双極子によるモデルを適用し回路
基板に対して電界プローブよりも遠方となる任意の位置
の電磁障害を予測演算する演算手段とを備えるものであ
り、回路基板の近傍に配置した電界プローブを用いると
ともに電気双極子によるモデルを適用して遠方の電磁障
害を予測するので、大型の設備が不要になるという利点
があり、また、電気双極子によるモデルを用いることに
よって回路基板の近傍の電界の測定により回路基板の遠
方まで精度のよい予測が可能になるという利点がある。According to a sixth aspect of the present invention, there is provided an electric field probe fixed at a fixed position near a circuit board to be measured for electromagnetic interference, and an electric field probe for electric field strength near the circuit board measured by the electric field probe. Calculating means for applying a model based on a dipole and predicting and calculating an electromagnetic interference at an arbitrary position farther than the electric field probe with respect to the circuit board, using an electric field probe arranged near the circuit board; By applying a model based on electric dipoles to predict electromagnetic interference at a distance, there is the advantage that large-scale equipment is not required.In addition, by using a model based on electric dipoles, the electric field near the circuit board can be measured. There is an advantage that accurate prediction can be performed up to a distant place of the circuit board.
【図１】本発明の実施形態に用いる装置の概略構成図で
ある。FIG. 1 is a schematic configuration diagram of an apparatus used in an embodiment of the present invention.
【図２】（ａ）（ｂ）はそれぞれ本発明のモデル作成に
用いた回路パターンの例を示す図である。FIGS. 2A and 2B are diagrams illustrating examples of circuit patterns used to create a model according to the present invention; FIGS.
【図３】本発明のモデルの概念図である。FIG. 3 is a conceptual diagram of a model of the present invention.
【図４】図２（ａ）の回路パターンの電流測定による予
測結果を示す図である。FIG. 4 is a diagram showing a prediction result by current measurement of the circuit pattern of FIG.
【図５】図２（ａ）の回路パターンの本発明方法での予
測結果を示す図である。FIG. 5 is a diagram showing a prediction result of the circuit pattern of FIG. 2A by the method of the present invention.
【図６】本発明のモデルと座標系との関係を示す図であ
る。FIG. 6 is a diagram showing a relationship between a model of the present invention and a coordinate system.
【図７】本発明のモデルの概念図である。FIG. 7 is a conceptual diagram of a model of the present invention.
【図８】図２（ｂ）の回路パターンの本発明方法での予
測結果を示す図である。FIG. 8 is a diagram showing a prediction result of the circuit pattern of FIG. 2B by the method of the present invention.
【図９】本発明方法による測定例を示す図である。FIG. 9 is a diagram showing a measurement example according to the method of the present invention.
【図１０】従来例に用いる測定具を示す平面図である。FIG. 10 is a plan view showing a measuring tool used in a conventional example.
【図１１】従来例を示す概略構成図である。FIG. 11 is a schematic configuration diagram showing a conventional example.
１ 回路基板 ２ 電界プローブ ４ コンピュータ ５ 固定台 １３ 電気双極子 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Electric field probe 4 Computer 5 Fixed base 13 Electric dipole
───────────────────────────────────────────────────── フロントページの続き (72)発明者 アダム ブリヴァント イギリス国 ケーティー22 ７エスエー サリーレザーヘッド クリーブロード イ ーアールエー テクノロジー リミテッド イーエムシー アドバンスト プロジェク ツ デパートメント内 (72)発明者 ジョン エイチ デュア イギリス国 ケーティー22 ７エスエー サリーレザーヘッド クリーブロード イ ーアールエー テクノロジー リミテッド イーエムシー アドバンスト プロジェク ツ デパートメント内 (72)発明者 吉田 和久 大阪府門真市大字門真1048番地松下電工株 式会社内 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Adam Brivant, Katie 227, United Kingdom SA Sally Leather Head Cleave Road IA Technology Limited, within the EMC Advanced Projects Department (72) Inventor, John H. Dua, United Kingdom Katie 227 S.A. Sally Leather Head Cleave Road I.R.A.Technology Limited EMC Advanced Projects Department Department
Claims (6)
傍に配置された電界プローブを用いて回路基板の近傍に
形成される電界の強度を測定し、測定された電界の強度
に電気双極子によるモデルを適用し回路基板に対して電
界プローブよりも遠方となる任意の位置の電磁障害を予
測演算することを特徴とする回路基板の電磁障害測定方
法。An electric field probe arranged near a circuit board to be measured for electromagnetic interference is used to measure the strength of an electric field formed near the circuit board, and the measured electric field strength is applied to an electric dipole. A method for predicting and calculating an electromagnetic interference at an arbitrary position farther than an electric field probe with respect to a circuit board by applying a model according to (1).
徴とする請求項１記載の回路基板の電磁障害測定方法。2. The method according to claim 1, wherein the electric field probe is non-directional.
に固定されることを特徴とする請求項１または請求項２
記載の回路基板の電磁障害測定方法。3. The electric field probe is fixed at a fixed position with respect to a circuit board.
The method for measuring electromagnetic interference of a circuit board as described in the above.
直交する線上に電界プローブを配置することを特徴とす
る請求項３記載の回路基板の電磁障害測定方法。4. The method according to claim 3, wherein the electric field probe is disposed on a line passing through the center of the circuit board and orthogonal to the surface of the circuit board.
度を、電気双極子の中心と電界プローブの中心と回路基
板の中心とを含む平面内において電気双極子と電界プロ
ーブの中心とを結ぶ直線に直交する成分とみなし、回路
基板に対して電界プローブよりも遠方となる任意の位置
の電磁障害を予測演算することを特徴とする請求項４記
載の回路基板の電磁障害測定方法。5. The electric field strength detected by the electric field probe is converted into a straight line connecting the electric dipole and the center of the electric field probe in a plane including the center of the electric dipole, the center of the electric field probe, and the center of the circuit board. 5. The method according to claim 4, wherein an electromagnetic interference at an arbitrary position that is farther than the electric field probe with respect to the circuit board is calculated by assuming orthogonal components.
傍の定位置に固定された電界プローブと、電界プローブ
により測定された回路基板の近傍の電界の強度に対して
電気双極子によるモデルを適用し回路基板に対して電界
プローブよりも遠方となる任意の位置の電磁障害を予測
演算する演算手段とを備えることを特徴とする回路基板
の電磁障害測定装置。6. An electric field probe fixed at a fixed position in the vicinity of a circuit board to be measured for electromagnetic interference, and an electric dipole model for an electric field strength near the circuit board measured by the electric field probe. And a calculating means for predicting and calculating an electromagnetic interference at an arbitrary position farther than the electric field probe with respect to the circuit board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34626996A JP3489363B2 (en) | 1996-12-25 | 1996-12-25 | Method and apparatus for measuring electromagnetic interference of circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34626996A JP3489363B2 (en) | 1996-12-25 | 1996-12-25 | Method and apparatus for measuring electromagnetic interference of circuit board |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10185973A true JPH10185973A (en) | 1998-07-14 |
| JP3489363B2 JP3489363B2 (en) | 2004-01-19 |
Family
ID=18382265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34626996A Expired - Fee Related JP3489363B2 (en) | 1996-12-25 | 1996-12-25 | Method and apparatus for measuring electromagnetic interference of circuit board |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3489363B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002228698A (en) * | 2001-02-02 | 2002-08-14 | Melco Inc | Electric field probe |
| ES2188408A1 (en) * | 2001-10-30 | 2003-06-16 | Fundacion Labein | System for the prediction of radiation emitted by an item of electronic equipment. |
| JP2010127698A (en) * | 2008-11-26 | 2010-06-10 | Nippon Telegr & Teleph Corp <Ntt> | Apparatus and method for estimation of radiated electromagnetic wave frequency |
| CN105929253A (en) * | 2016-06-15 | 2016-09-07 | 北京航空航天大学 | Method using dipole moment model to inverse PCB circuit electromagnetic field |
| US9977062B2 (en) | 2014-08-27 | 2018-05-22 | Fujitsu Ten Limited | Electric field intensity calculation program, electric field intensity calculation apparatus and electric field intensity calculation method |
| CN112834843A (en) * | 2020-12-31 | 2021-05-25 | 江苏南高智能装备创新中心有限公司 | Radio frequency integrated circuit near field electromagnetic compatibility test management method and system |
| CN113391205A (en) * | 2021-07-19 | 2021-09-14 | 德丰电创科技股份有限公司 | Device and system for verifying immunity of constant magnetic field |
-
1996
- 1996-12-25 JP JP34626996A patent/JP3489363B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002228698A (en) * | 2001-02-02 | 2002-08-14 | Melco Inc | Electric field probe |
| ES2188408A1 (en) * | 2001-10-30 | 2003-06-16 | Fundacion Labein | System for the prediction of radiation emitted by an item of electronic equipment. |
| JP2010127698A (en) * | 2008-11-26 | 2010-06-10 | Nippon Telegr & Teleph Corp <Ntt> | Apparatus and method for estimation of radiated electromagnetic wave frequency |
| US9977062B2 (en) | 2014-08-27 | 2018-05-22 | Fujitsu Ten Limited | Electric field intensity calculation program, electric field intensity calculation apparatus and electric field intensity calculation method |
| CN105929253A (en) * | 2016-06-15 | 2016-09-07 | 北京航空航天大学 | Method using dipole moment model to inverse PCB circuit electromagnetic field |
| CN105929253B (en) * | 2016-06-15 | 2018-10-02 | 北京航空航天大学 | The method that inverting is carried out to PCB circuit electromagnetic fields using dipole moment model |
| CN112834843A (en) * | 2020-12-31 | 2021-05-25 | 江苏南高智能装备创新中心有限公司 | Radio frequency integrated circuit near field electromagnetic compatibility test management method and system |
| CN112834843B (en) * | 2020-12-31 | 2023-12-19 | 江苏南高智能装备创新中心有限公司 | Near-field electromagnetic compatibility test management method and system for radio frequency integrated circuit |
| CN113391205A (en) * | 2021-07-19 | 2021-09-14 | 德丰电创科技股份有限公司 | Device and system for verifying immunity of constant magnetic field |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3489363B2 (en) | 2004-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yan et al. | A miniature ultrawideband electric field probe based on coax-thru-hole via array for near-field measurement | |
| JP4130365B2 (en) | Method and apparatus for measuring electromagnetic field strength, method for measuring electromagnetic field intensity distribution, and method and apparatus for measuring current-voltage distribution of the apparatus | |
| Xiang et al. | A particle swarm optimization-based approach for predicting maximum radiated emission from PCBs with dominant radiators | |
| He et al. | An ultrawideband magnetic probe with high electric field suppression ratio | |
| Zhang et al. | An efficient probe calibration based near-field-to-near-field transformation for EMI diagnosis | |
| US6483304B1 (en) | Magnetic field probe having a shielding and isolating layers to protect lead wires extending between a coil and pads | |
| Wang et al. | A simple method for predicting common-mode radiation from a cable attached to a conducting enclosure | |
| JP3489363B2 (en) | Method and apparatus for measuring electromagnetic interference of circuit board | |
| Spang et al. | Application of probes with multiple outputs on probe-compensated EMC near-field measurements | |
| Sayegh et al. | Analytical solution for maximum differential-mode radiated emissions of microstrip trace | |
| JPH10311857A (en) | Near magnetic field probe, near magnetic field probe unit, near magnetic field probe array, and magnetic field measuring system | |
| Pillai et al. | Derivation of equivalent circuits for multilayer printed circuit board discontinuities using full wave models | |
| CN115856742A (en) | Near-zone magnetic field probe accurate calibration system and method for electromagnetic compatibility pretest | |
| Dimitrijević et al. | Calibration of the loop probe for the near-field measurement | |
| Kazama et al. | Adjacent electric field and magnetic field distribution measurement system | |
| Sivaraman et al. | Three dimensional scanning system for near-field measurements | |
| JP2008082945A (en) | Near electromagnetic field distribution measurement apparatus | |
| JP5170955B2 (en) | Electromagnetic wave measuring method and electromagnetic wave measuring device | |
| Fano et al. | Near field magnetic probe applied to switching power supply | |
| Volski et al. | Auxiliary dipoles to compensate for the finite size of the planar scanning area in near-to-far-field transformations | |
| JP3481795B2 (en) | Design method of noise measurement device and noise detection coil | |
| Kam et al. | On different approaches to combine cable information into near-field data for radiated-field estimation | |
| JP2012181161A (en) | Electromagnetic radiation source detection method and apparatus | |
| JP2011017535A (en) | Distant electromagnetic field noise measuring method and device | |
| Yuan et al. | An optimization method for conformal shielding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20031007 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081107 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081107 Year of fee payment: 5 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091107 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091107 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101107 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111107 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121107 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |