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COAXIAL CABLES • ELECTRICAL PARAMETERS
In
order to choose the right coaxial cable, it is first necessary
to consider the electrical parameters.
Following are the four main parameters:
1)
Attenuation:
represents the decrease in intensity that the signal undergoes
while crossing the cable. It is generally measured in dB/100 m.
Attenuation
is a function of the frequency of the signal, and the length and
physical structure of the cable itself. Specifically, it depends
on:
- the diameter of
the inner conductor: as the diameter of the conductor increases,
attenuation decreases.
- The composition
of the outer conductor: the more effective the screening action,
the lower the attenuation.
- The nature of
the dielectric: the lower its constant dielectric, the lower
the attenuation. Therefore, an expanded dielectric supplies,
at any given diameter, values of attenuation lower than a solid
dielectric.
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