Coaxial cable from the inside out is divided into four layers: the central copper (single strand of solid or stranded strand), plastic insulator, mesh conductive layer and wire sheath. The central copper wire and the mesh conductive layer form a current loop. Because the central copper wire and mesh conductive layer for the coaxial relationship named.
Coaxial cable conduction AC rather than direct current, that is, every second there will be several times the direction of the current reversal.
If a high-frequency current is transmitted using a general wire, the wire will correspond to an antenna that emits radio outwards, which forces the power of the signal so that the received signal strength decreases.
Coaxial cable design is to solve this problem. The radio from the center wire is isolated by the mesh-like conductive layer, and the mesh-like conductive layer can control the emitted radio by grounding.
Coaxial cable also has a problem, that is, if a cable over a large extrusion or twisting deformation, then the central wire and the conductive layer between the distance is not always consistent, which will cause the internal radio waves will be Reflected signal source. This effect reduces the available signal power. In order to overcome this problem, the center wire and mesh conductive layer is added between a layer of plastic insulators to ensure that the distance between them is always the same. This also causes the cable to be stiff and not easy to bend.