What are "unnecessary electromagnetic waves"?

"Unnecessary electromagnetic waves" are waves that are unintentionally radiated from various kinds of equipment under normal operating conditions. Electromagnetic waves emitted from radio transmitters may also be regarded as "unnecessary electromagnetic waves", if they negatively affect the others. Likewise, electromagnetic waves generated by natural phenomena such as lightning can be regarded as "unnecessary electromagnetic waves".



Effects of "unnecessary electromagnetic waves"

"Unnecessary electromagnetic waves" may degrade the operation of devices that use electromagnetic waves as well as of those that do not. They may degrade the quality of operation or may even cause a malfunction. They may also interfere with signal reception in wireless communication and broadcasting services.


不要電波障害を低減するには、不要電波の抑制および妨害排除能力の向上の両面から適切な対策を行い、正常な動作を確保する必要があります。このような不要電波を出す側および受ける側の電磁環境における両立性を国際的にはEMC(Electromagnetic Compatibility)と呼んでいます。


To reduce the harmful effects of "unnecessary electromagnetic waves", unintentional emitters must be improved to suppress their emission. Devices that receive the waves must also be improved to make them more robust against such waves. This compatibility between emitters and receivers is called "electromagnetic compatibility (EMC)"



Purpose of EMCC

"Unnecessary electromagnetic waves" have become a serious problem in modern environments, and thus the taking of effective countermeasures against them has become an important issue. Since a variety of devices generate such waves, either as part of their designed function or not, many government agencies, manufacturers, and user organizations are addressing this issue.

Representative parties from each of these areas established the EMCC on September 17, 1987 as a forum for exchanging information and discussing measures to prevent harmful effects of these waves.