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As far as i know,electronic components like processors and other chips that contains switching transistors are emitting radiation that can be at frequencies of kHz,mHz and gHz.I read that these radiation propagates along the conductors and cables which acts as antennas. My question is:Does the radiation that those chips creates is actually RF waves that are transmitted to the space(as the cell phones does)or they only creates an EMF that alternating just along and around the conductors(like 50/60hz power-line radiation behaves)while they don't transmit any wave to the space?

Thanks.

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First, I'm not familiar with the term "EMF radiation" for this effect. I'd call it "near field interference". I wouldn't call it "radiation" because it doesn't radiate --- it's confined to the region near the source.

As for the actual question, both effects will be present.

A chip producing or using GHz signals will produce some radiation. Since the frequency is in the gigahertz, it is RF radiation. Higher frequency signals tend to radiate more strongly because the dimensions of the antenna required to couple them to free space efficiently are smaller. Generally there are regulations and legislation that require the designer to limit this radiation.

There will also be some local fields produced (near-field effects). These can cause interference with nearby components. However, the effect is typically not strong in the scenario you described. As an experienced electronics designer I have never seen a design fail due to near-field signals from a high-frequency component. Near-field signals from a large inductor operating at modest (100 kHz or so) frequencies is another story.

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  • $\begingroup$ What about a chip that using/producing MHz signals and its signals propagate along a cable that its length is equal to this MHz wave's length like a wired mice of computer.Will in this case the cable of the mice will also emit RF radiation to the space and will produced also near field effect? $\endgroup$
    – xchcui
    Commented Jan 5, 2021 at 19:00
  • $\begingroup$ @xchcui, In the electromagnetic compliance (EMC) world that is called conducted emissions. It is restricted by regulations and legislation like radiated emission. $\endgroup$
    – The Photon
    Commented Jan 5, 2021 at 19:02
  • $\begingroup$ ,once i found,by a very cheap detector,that there is a kind of radiation,in the MHz frequencies range,along the cables of the mice and the keyboard.I understand that it is called conducted emissions,but in my case,did the cables actually emit radiation to the space? $\endgroup$
    – xchcui
    Commented Jan 5, 2021 at 19:31
  • $\begingroup$ @xchcui, Take the parts to a well-equipped test lab and they can tell you. If you can measure the emission more than 2-3 wavelengths away from the source, then it is radiating. $\endgroup$
    – The Photon
    Commented Jan 5, 2021 at 19:34
  • $\begingroup$ Okay,lets say that the mice cable is 1.8 meter long and there is a conducted emission in the 166MHz frequency on the cable.Wouldn't this energy turns to a radiated emission and radiate to the space,since the cable length is fit to the wavelength on this frequency? $\endgroup$
    – xchcui
    Commented Jan 6, 2021 at 10:45

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