High frequency performance of structured wire cabling in communication systems
Twisted pan (structured wire) cabling is a principal component in the
communications infrastructure, with millions of meters being installed weekly.
The rate of increase in upper frequency for this cable appears to be doubling
approximately every two years. Clearly, a rigorous approach to the design of
these cables is fundamental to achieving data transmission at these frequencies
with increasingly stringent performance requirements.
This thesis derives a family of equations for the secondary parameters based on
an explicit relationship between cable dimensions and materials. These equations
have been validated against experimental results and fOWld accurate. Further.
equations are developed which calculate the overall S-parameters for cascaded
multi.pair cables, the return loss and cross-talk between transmission charmels.
In tenns of cable specification. the secondary parameters are the most significant
with many of the perfonnance criteria based on these. With designs based largely
on the manipulation of physical dimensions, there has been no family of
secondary parameter equations given explicitly as functions of cable dimensions
and material properties. Similarly, tools have not existed to allow the
investigation of design variability or the effects of handling and installation.
These are principal requirements in the cable design process.
A modelling package, based on Transmission-Line Matrix (TLM) modelling, is
developed to a1low the investigation of manufacturing variability and installation
handling effects on overall perfonnance of a cable. This modelling technique is
validated against both experimental results and analytical results the comparison
Finally a novel method for the calculation of cross talk between cable pairs is
presented. This method is based on a hybrid field·circuit model. Comparisons
with measurements show good agreement.