Why does a copper cable with higher frequency signals attract more attenuation? Looking at this article here by Techopedia, The writer notes that the higher the frequency of a signal in copper cabling, the higher the attenuation across the cable. Why is this the case?

One of the main reasons is skin effect:

> Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor, and decreases with greater depths in the conductor. The electric current flows mainly at the "skin" of the conductor, between the outer surface and a level called the skin depth. The skin effect causes the effective resistance of the conductor to increase at higher frequencies where the skin depth is smaller, thus reducing the effective cross-section of the conductor.

Litz wire was designed to minimize the effects.