The Shielded twisted pair STP

In Twisted pair cables two conductor wires are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources AC DC motors, generators, electric main supply lines of one phase or three phase carrying high current and crosstalk between neighboring pairs. Two basic types of twisted-pair cable exist: unshielded twisted pair (UTP) and shielded twisted pair (STP). Shielded twisted-pair (STP) cable combines the techniques of shielding, cancellation, and wire twisting. Each pair of wires is wrapped in a metallic foil.They have usually 150-ohm impedance. The use of STP is in Ethernet network installations, because STP reduces electrical noise both within the cable which may be due topair-to-pair coupling, or crosstalk and from outside the cable for example EMI and RFI. STP is installed with STP data connector, which is created especially for the STP cable. The Speed and throughput of STP cables may ranges in 10 to 100 Mbps with Maximum cable length is 100 m. The construction of STP cables has following four layers,

• Plastic cover - outer most layer
• Metal shield or metal grid or mesh
• Insulation of each individual copper wire
• Cooper wire