Choosing the Right Double Shielded Coax Cable for Your Needs
Double shielded coaxial cables are a type of high-performance cable that is used in a variety of applications, including video, audio, and data transmission. They offer superior protection against electromagnetic interference (EMI) and radio frequency interference (RFI) than single shielded cables, making them ideal for use in sensitive environments. When choosing a double shielded coax cable, there are several factors to consider to ensure you select the right one for your needs.
Conductor Material and Gauge
The conductor material and gauge play a significant role in the cable’s performance and durability. Copper is the most commonly used conductor material for coax cables due to its excellent conductivity and resistance to corrosion. The gauge, measured in American Wire Gauge (AWG), indicates the thickness of the conductor. A lower gauge number indicates a thicker conductor, which provides better signal transmission and less attenuation.
Shielding Material and Construction
The shielding of a double shielded coax cable consists of two layers of conductive material, typically copper or aluminum foil. The outer shield provides protection against external EMI and RFI, while the inner shield helps to reduce interference between the signal-carrying conductor and the outer shield. The shielding effectiveness is measured in decibels (dB), with higher values indicating better protection.
Dielectric Material
The dielectric material, which insulates the conductor from the shielding, affects the cable’s capacitance and impedance. Common dielectric materials used for coax cables include polyethylene, foamed polyethylene, and Teflon. Polyethylene is widely used due to its low cost and good electrical properties, while foamed polyethylene offers lower capacitance and better flexibility. Teflon is the most expensive option but provides excellent thermal stability and high-frequency performance.
Jacket Material and Construction
The jacket of a coax cable protects the inner components from mechanical damage and environmental factors. Common jacket materials include PVC, polyethylene, and polyurethane. PVC is the most commonly used due to its low cost and flexibility, while polyethylene offers better UV resistance and polyurethane provides increased durability against abrasion and chemicals.
Impedance and Capacitance
Impedance and capacitance are two important electrical characteristics of coax cables. Impedance refers to the resistance that the cable presents to the signal, while capacitance measures the ability of the cable to store electrical charge. The impedance should be matched with the impedance of the equipment being connected, and the capacitance should be low enough to minimize signal distortion.
Other Considerations
In addition to the above factors, there are a few other considerations to keep in mind when choosing a double shielded coax cable. These include the length of the cable, the connectors that are required, and any special requirements for the application. By carefully evaluating these factors, you can select the right double shielded coax cable that meets your specific needs and ensures optimal performance.