Noise Suppression Products/EMI Suppression Filters

Chapter 4

Spatial conduction and its countermeasures

4-5. Summary of Chapter 4

Chapter 4 has described the spatial noise conduction and shielding. The electromagnetic concepts used for explaining noise have also been introduced. The relationship of topics and concepts described in this section is as follows:

Relationship of topics

Fig. 4-5-1 Relationship of topics

Noise needs an antenna to be emitted. However, the characteristics of an antenna can vary depending on its physical shape and it is difficult to express an antenna as a circuit. This fact is making it difficult to understand noise problems and design circuits. This chapter has described antennas by simplifying the model so as to understand the entire picture of the spatial noise conduction.
Although the description mainly focuses on the noise occurrence, the same concept comes in useful for the case of receiving noise. An antenna that can easily emit noise is also an antenna that can easily receive noise.
It is natural for noise to be emitted when it is conducted through an antenna. Therefore, electronic devices are generally designed so as not to conduct noise as much as possible while the wiring is designed so as not to work as an antenna. You may consider that the reason why noise causes a problem is that the noise current can take an unexpected route. This phenomenon will be explained in the noise mode conversion. The next chapter will describe noise mode and mode conversion.

Summary of Chapter 4

Fig. 4-5-2 Summary of Chapter 4

[Japanese] 環境電磁工学の基礎
電子情報通信学会 1991
Noise Reduction Techniques in Electronic Systems Second Edition
Henry W. Ott
John Wiley & Sons, Inc. 1988
[Japanese] 電磁妨害波の基本と対策
清水康敬, 杉浦行
電子情報通信学会 1995
Introduction to Electromagnetic Compatibility
Clayton R, Paul
John Wiley & Sons, Inc. 1992

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