The Basics of Double Shielded Coax Cable- An Introduction
Double shielded coaxial cable, often known as double-shielded coax, is a type of coaxial cable that offers superior signal protection and noise immunity compared to its single-shielded counterpart. It features two layers of shielding, providing an extra barrier against electromagnetic interference (EMI) and ensuring the integrity of the signal being transmitted.
Construction and Design
Double shielded coax cable consists of a central conductor, typically made of copper or copper-clad steel, surrounded by a layer of dielectric insulation. This dielectric material serves to separate the central conductor from the outer shielding layers. The first layer of shielding, known as the braid shield, is typically constructed from braided copper or aluminum and provides a high degree of EMI protection. Over this braid shield is a second layer of shielding, often referred to as the foil shield. The foil shield is a thin layer of conductive material, usually aluminum, and serves to enhance the EMI protection provided by the braid shield.
Shielding Effectiveness
The effectiveness of double shielded coax cable in mitigating EMI is measured by its shielding effectiveness (SE). SE is expressed in decibels (dB) and indicates the amount of attenuation provided by the cable. The higher the SE, the better the protection against EMI. Double shielded coax cables typically offer SE values in the range of 100 dB to 150 dB, providing excellent protection against electrical noise and interference.
Applications
Double shielded coax cable is commonly used in applications where high-quality signal transmission is critical and EMI protection is paramount. Some of the most common applications include:
– Video and audio broadcasting: Double shielded coax cable is used to transmit video and audio signals in broadcast systems, ensuring the delivery of high-quality content with minimal interference.
– Satellite communications: Double shielded coax cable is employed in satellite dishes and other satellite communication equipment to connect to satellites and receive signals with high reliability and noise immunity.
– Industrial and military systems: Double shielded coax cable is utilized in industrial and military applications where high-performance data transmission and protection from electrical noise are essential.
– Data centers and networking: Double shielded coax cable is deployed in data centers and networking environments to connect servers, switches, and other network equipment, ensuring reliable and secure data transmission.
Advantages and Disadvantages
Advantages:
– Superior EMI protection and noise immunity
– Excellent signal quality and reliability
– Durable and long-lasting
– Compatible with a wide range of applications
Disadvantages:
– More expensive than single-shielded coax cable
– Less flexible and more difficult to route
– Requires specialized connectors and installation techniques