For the coaxial cable, better shielding equals less signal interference, so that's one good way to measure a cable's quality. Types of shielding can vary greatly, as can the amount present from one cable to next – coaxial cable can be had from 1 to 4 layers shielding. in the sequence of AL Foil, Braiding, AL Foil, Braiding. The best coaxial shields are the ones that offer the highest density, or percentage of cover. Tightly-woven metal braid makes an excellent choice – not only is it highly conductive, it can provide as much as 95% coverage.
The construction of shielding for coaxial cable as below:
1, Single shield：Only one layer of Aluminium Foil
2, Double shield: Aluminium Foil + Braiding, its material for braiding can be: Al-Mg alloy wire, CCA or Copper.
3, Trip shield: Aluminium Foil + Braiding + Aluminium Foil.
4, Quad shield：Aluminium Foil + Braiding + Aluminium Foil + Braiding