Industry News

♦ RF coaxial cable selection guide


Need to consider the properties, when select the most appropriate communication coaxial cable.
A. Signal reflections: VSWR and impedance consistency .
·signal transmitted to the other end of the cable , VSWR ≤1.1:1;
·signal converted into heat or leaked from the cable, when signal propagated along the cable.
·signal reflect back towards to the cable input. Caused by impedance changes along the cable length direction.
B. Attenuation
Attenuation is the loss of signal propagation along the cable, when the RF signal through the cable, part of the transition into the hot, part leaked through the outer conductor.
Attenuation is determined by the conductivity and dielectric loss of the cable. big size cable have little conduction loss, thus attenuation is little.
C. Average power rating
The power loss in coaxial cable caused by the heat that generated in the dielectric, inner and outer conductors. Power capacity of the cable depend on its cooling capacity.
D. Shielding and crosstalk
The shielding efficiency depends on the structure of the outer conductor, the most common structure:
Single braid: bare copper or tinned copper or silver-plated copper (70% -90% coverage)
Double braid: two single-woven layer, with no insulating layer.
Three braid: two single-woven layer, the middle insulating layer.
E. The stability of the electrical length
The antenna feed system applications may need cable assemblies, these components are tuned to a specific electrical length. The cable length changes with temperature, bending, tension and other environmental factors is very important, especially in the Phased array system.
F. Operating temperature range
Flexible cable operating range is determined mainly by the temperature operating range of the dielectric and jacket material. Silver-plated conductors Suitable for long-term work in the environment over 80 ℃.
G. Flexibility
Stranded wire center conductor and the braided outer conductor of the coaxial cable is used to repeat the bending , the more qty of stranded wires, the better cable flexibility, the bigger attenuation.
H. Intermodulation
Passive intermodulation test, cables need high index requirements for connectors, even the connection of the cable .
I. Environment adaptability
The characteristics of coaxial cable depends on many factors, ultraviolet radiation, high humidity, electro-chemical reaction, corrosion of sea water and steam are the main reasons for cable damage. Chloride coat of ethylene polymers is 1/2 less lifetime than the appropriate compound of polyethylene.

Hits:  Printing  Close