Shielded cable is a type of conductive cable called shielded cable. The wrapped wire is called a shielding layer, usually made of braided copper mesh or copper foil (aluminum). The shielding layer needs to be grounded, and external interference signals can be introduced into the ground. Its function is to prevent interference signals from entering the inner layer while reducing the loss of transmitted signals.
Shielded cables have both ordinary and advanced structures. The ordinary structure consists of an insulation layer, a shielding layer, and a conductor. The structure consists of an insulation layer, a shielding layer, a signal conductor, and a shielding layer grounding conductor. The shielded wiring system originated in Europe. It adds a metal shielding layer to the exterior of a regular unshielded cabling system. It utilizes the reflection, absorption, and skin tilt effects of metal shielding layers to prevent electromagnetic interference and radiation. The shielding system comprehensively utilizes the balance principle of twisted pair cables and the shielding function of the shielding layer, and has good electromagnetic compatibility (EMC) characteristics. The shielding principle of shielded cables is different from the balanced cancellation principle of twisted pair cables. Shielded cable is a type of cable that adds one or two layers of aluminum foil to the outside of four pairs of twisted pair wires. It utilizes the principles of metal reflection, absorption, and skin contraction effect on electromagnetic waves (the skin contraction effect refers to the distribution of current on the cross-section of a conductor. As the frequency increases, the surface distribution of the conductor tends to increase. The higher the frequency, the smaller the depth of skin contraction, which means that the higher the frequency, the weaker the penetration ability of electromagnetic waves), effectively preventing external electromagnetic interference from entering the cable and preventing internal signal radiation from interfering with the operation of other devices
