What is Computer Signal Shielded Cable?

A Computer Signal Shielded Cable is a special type of cable designed to reduce interference from external electromagnetic fields on computer signal lines and prevent the lines from radiating electromagnetic energy outward.

The following is a detailed introduction:

Functions

Prevent electromagnetic interference: On one hand, it can resist electromagnetic interference generated by external electronic devices and power lines, creating a Faraday cage effect to block the penetration of external electromagnetic fields. On the other hand, it can prevent signal crosstalk when multiple cables are laid densely, confining the electromagnetic field of each cable within its own range.

Prevent signal leakage: For Computer Signal Cables that transmit sensitive information, the shielding layer can prevent internal signals from radiating outward, ensuring information security. It also helps reduce electromagnetic radiation from the cables to the outside, making the entire system comply with Electromagnetic Compatibility (EMC) standards.

Improve signal transmission quality: By reducing electromagnetic interference and preventing signal leakage, it maintains signal integrity, ensuring that signals are not distorted or attenuated during transmission and lowering the bit error rate.

Structure

It generally consists of a conductor, an insulation layer, a shielding layer, and an outer sheath. 

- The conductor is mostly made of multiple fine bare copper wires or tinned copper wires twisted into a bundle.

- The insulation layer is made of materials such as PVC.

- The shielding layer usually has structures like aluminum foil Mylar tape wrapping and (tinned) copper wire braided shielding. Some cables also have optional structures such as insulation plastic film wrapping or special PVC mixture inner sheaths.

- The outer sheath is generally made of PVC mixture.

Types

Classified by shielding layer material and structure: There are various types such as aluminum foil shielded cables, braided mesh shielded cables, F/UTP (single-layer aluminum foil shielding structure), SF/UTP (double-layer shielding structure of aluminum foil and copper braided mesh), and F/FTP (pair shielding + total aluminum foil shielding).

Classified by working nature and structure: It can be divided into ordinary shielded cables, twisted-pair shielded cables, Coaxial Cables, etc.

Key Selection Points

Consider the type: Choose based on the application scenario. For example, shielded twisted-pair cables can be used for local area networks, coaxial cables for video signal transmission, and optical fiber cables for large-data-volume transmission with extremely high requirements for electromagnetic interference resistance.

Pay attention to shielding grade: The higher the shielding grade, the stronger the anti-interference performance. Select cables with single-layer shielding, double-layer shielding, or fully enclosed shielding according to the actual environment.

Evaluate conductor material and cable characteristics: Copper is the preferred conductor material. Meanwhile, pay attention to the cable's characteristic parameters such as resistance, capacitance, and inductance, as well as the operating temperature range.

Focus on certifications and manufacturer reputation: Choose products certified by UL, CE, etc. Products from well-known manufacturers offer better quality and after-sales service guarantees.

Installation Precautions

Ensure a suitable environment: The installation environment should be dry and clean, avoiding moisture and corrosive substances.

Wire according to specifications: Follow the correct method for wiring to ensure a firm and reliable connection between the cable and the equipment.

Fix and protect: Use appropriate clamps or brackets to fix the cable to prevent damage caused by vibration or stretching.

Ground correctly: Ensure a good connection between the shielding layer and the grounding terminal of the equipment to achieve the shielding effect.