@David Ashton: it is a simple setup to generate these plots in a 2D Emag Field Solver. You can download the Student Version of Sonnet (Lite, Version 13) and generate the current distribution plots. Note that many of these solvers require you to manually mesh the (free) space around the conductors with elements and some may need infinite boundary definitions (depending on the solution technique used: finite elements, boundary integrals, etc.)
Dr. MP Divakar
There is an error in the units next to the formula, the depth unit should be "um" (micron). So for, 1 MHz, we should have a skin depth of 0.076mm or 76um... so for example, a 2-mil wide & deep trace conducting at 1-MHz, it will be all of the cross section conducting current.
Good article none-the-less.
Dr. MP Divakar
Can the author or someone else tell me how the diagrams above were arrived at? I don't doubt their accuracy - "Skin Effect" is a very well known phenomenon - but how do you measure the current INSIDE a wire?
It is nice to see examples of how the fundamental laws affect circuit performance and this is certainly an effect that is measurable. Mr. Stearn's question about Litz wire is correctly directed to the effect in this Tip. Litz wire has improved the unloaded Q of inductors for me in filters in the VHF band.
I believe there is an error in the coefficient in this Tip's first equation, it should be 1000 times smaller, and a more exact coefficient is 6.6e-3 for copper.
Thank you for your paper.
I've never been able to find any information on
using the skin effect to create non-linear filters, yet clearly if the resistance of an inductor changes with frequency, the filter characteristics will change.
Also, what's your opinion on Litz wire?
Scottsdale Arizona US
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