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I've read that at high AC frequencies, current concentrates near the surface of a conductor, which is known as the skin effect. Does this also mean that current concentrates near the edge of thin metals? Specifically, I'm simulating (with OpenEMS) a gaussian pulse (\$0-18\,\text{GHz}\$) propagating down a microstrip transmission line. When I view the current density as a function of time, I see this

enter image description here

As you can see, the current density is greater near the edges of the microstrip than at the center. Is my simulation a qualitatively accurate representation of reality? Why would currents concentrate near the edge?

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  • \$\begingroup\$ Sorry, all of your questions have been answered before. Just type in skin effect to the search box, plenty of info. \$\endgroup\$
    – GB - AE7OO
    Commented Apr 8, 2020 at 4:13
  • \$\begingroup\$ Not that I've seen. I've seen plenty about skin effect, but not for the edges of thin conductors, just generally about keeping current near the surface of some metal. So, why doesn't the current concentrate around the entire surface, why just the edges? If this is obvious to you please explain, or link to an answer that actually answers this specific question. \$\endgroup\$
    – MattHusz
    Commented Apr 8, 2020 at 4:31
  • \$\begingroup\$ I know the basics, but for a in depth description you could wait for Tony to come around and get a description in depth, one that would most likely take me 4 or 5 readings to understand, if I was lucky..LOL. On the other hand the Wikipedia article does a pretty good job explaining it: en.wikipedia.org/wiki/Skin_effect Sorry, I'm more a tech than an engineer.. \$\endgroup\$
    – GB - AE7OO
    Commented Apr 9, 2020 at 5:09

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The idea that the current runs along the surface only makes sense for conductors which have a ‘normal’ cross section like a round wire. Here the current will tend towards the edge / surface in all directions equally.

On the other hand with a very flat/wide trace the current will also tend towards the edge and get the fittest away from the center. So it will go to the sides and not up/down.

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