Skin Effect and Surface Currents

Skin Effect and Surface Currents image #1 Skin Effect and Surface Currents image #2

11 May 2021

Author: Keith Armstrong

Skin Effect and Surface Currents

Understanding skin effect and surface currents saves us a lot of time and cost in the design of our product's shielding and filtering, especially for tough EMC standards such as automotive, military or aerospace. It also helps us to more quickly achieve many other issues in cost-effective EMC design.

This is because visualizing skin effect and surface currents is much easier than trying to picture what is really going on – the propagation of electromagnetic (EM) waves and fields – and so it more easily provides valuable insights into good EM engineering.

Note:   ‘EM engineering’ includes the design disciplines of signal integrity (SI), power integrity (PI) and electromagnetic compatibility (EMC).

Without using good EM engineering, no electronics company can now expect to be financially successful.

Few electronic, mechanical or PCB designers (or their managers) are taught anything about good EM engineering during their academic schooling, so there is a massive gap between what they need to know for the financial success of their employers, and what they actually do know.

Skin effect is (effectively) a ‘Law of Nature’ – i.e. unavoidable – so if we try to design without respecting it, we will cause difficulties for ourselves (and, more importantly, for our customers and our employers).

However, when we understand skin effect and its natural consequences – surface currents – we can more easily visualise what is really going on with the EM waves and fields.

This makes it easier to do good SI, PI and EMC design more quickly:          

  • amazing our colleagues;     
  • confounding our competitors;        
  • and leaving us basking warmly in the respect of our peers.

For more details on this important technique, read my article in In Compliance magazine, July 2018 Edition.

Or read the version of that article that is posted on EMCstandards.

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