But at a higher frequency? Smaller wavelength?
Also, the other side — skin effect which can increase the current density?
My experience with higher frequencies is that they tend to not propagate well through an enclosure or system. So by the time the energy hits the circuit in question, it is greatly attenuated. Then again, I could be wrong.
On the other hand, engineers are not designing for susceptibility at higher frequencies. Only enough to pass the regulatory requirements (with some margin). But as a general rule, good “RF design” will offer some immunity.
generally, for EMC purposes, higher frequencies (radiated) penetrate into an enclosure better than lower frequencies.
lower frequencies conduct better than higher frequencies into enclosures.
However, higher frequencies couple into cables of typical dimensions better than lower frequencies.
You’re right. Good RF design comes into play for EMP tolerance.