Page "Coaxial cable" Paragraph 10

Many conventional coaxial cables use braided copper wire forming the shield.

This allows the cable to be flexible, but it also means there are gaps in the shield layer, and the inner dimension of the shield varies slightly because the braid cannot be flat.

Sometimes the braid is silver-plated.

For better shield performance, some cables have a double-layer shield.

The shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid.

Some cables may invest in more than two shield layers, such as " quad-shield ," which uses four alternating layers of foil and braid.

Other shield designs sacrifice flexibility for better performance ; some shields are a solid metal tube.

Those cables cannot take sharp bends, as the shield will kink, causing losses in the cable.