What does shielded wire mean?

　　A shielded cable is a special type of cable. Its definition, principle, and related information are as follows:

　　I. Definition

　　A shielded wire is a wire that directs that another conductor is wrapped around the outside of the body. This outer-wrapped conductor is called a shield, and is usually made of woven copper mesh or copper foil (sometimes aluminum). The shield is designed to direct external interference signals into the earth, thereby protecting the signal tranSMission of the internal conductor from interference.

　　Principle

　　The shielded wire blocks or reduces the influence of electromagnetic interference (EMI) and radio frequency interference (RFI) on the signal transmission of the internal conductor through its shielding layer. As a conductive material, the shielding layer can effectively isolate the interference signal from the main signal, improving the purity and stability of the signal. When the shielding layer is grounded, external interference signals can be introduced into the earth, thereby preventing these signals from interfering with the internal conductor.

　　III. Structure

　　The basic structure of a shielded wire includes an insulating layer, a shielding layer, and a conductor. Advanced structure shielded wires may also include signal conductors and shielded ground conductors. Depending on the shielding layer, shielded wires can be divided into various types, such as single-layer aluminum foil shielding (F/UTP), aluminum foil and copper braided mesh double-layer shielding (Foil). And Braided Screened Cable).

　　IV. Function

　　Anti-interference: The main function of the shielded wire is to prevent interference signals from invading the inner conductor and reduce the loss of the transmission signal. It can effectively resist the influence of external electromagnetic interference and radio frequency interference to ensure the integrity of signal transmission.

　　Radiation protection: The shielded wire also prevents the line from radiating electromagnetic energy outward, thus reducing electromagnetic pollution to the surrounding environment.

　　V. Precautions

　　Grounding method: The grounding method of the shield layer has an important impact on its anti-interference effect. Generally speaking, a single-layer shield should be grounded at one end to avoid the formation of a potential difference; while a double-layer shield may use a more complex grounding method, such as grounding at both ends of the outermost shield and grounding at one end of the inner shield. However, it should be noted that the shield layer should not allow multi-point grounding, because multi-point grounding may form a current circuit, but introduce interference.

　　Material selection: The material of the shield layer is usually selected from metals with good electrical conductivity, such as copper or aluminum. These materials can effectively introduce interference signals into the earth.

　　Application scenarios: Shielded wires are widely used in applications that require high-quality signal transmission, such as communications, broadcasting, television, computers, etc. In these fields, electromagnetic interference and radio frequency interference have a particularly significant impact on signal transmission, so shielded wires are required to ensure signal stability and integrity.

　　To sum up, shielded wire is a kind of cable with special structure and function, which blocks or reduces the influence of electromagnetic interference and radio frequency interference on the signal transmission of internal conductors through its shielding layer. In situations where high-quality signal transmission is required, shielded wire plays an important role.