Electromagnetic Compatibility in Wireline Communications
Abstract
This document is a thesis submitted in partial fulfilment of the requirements of the University
of Hertfordshire for the degree of Doctor of Philosophy (Part Time) in 'EMC in Wire-line
Communications' in the School of Electronic, Communication and Electrical Engineering at the
University of Hertfordshire. It describes a programme of research into the modelling and
measurement of radio frequency interference emissions from various communication networks
including Power Line (Tele)communications (PLC/PLT) and Digital Subscriber Line (DSL).
An introduction and literature review are followed by the results of practical measurements on
installed networks. These measurements include antenna gain and Longitudinal Conversion
Loss (LCL). Power line communication networks, splitterless DSL and home phoneline
networks in buildings are studied and modelled and the models are compared with the
measured results.
Improved EMC test methods are also described, in particular the modelling and design of four
types of portable antennas for use in radiated EMC measurements with improved sensitivity at
frequencies up to 30 MHz. The first type is a set of three manually tuned loop antennas
covering 100 kHz - 30 MHz. The second is a set of three loop antennas that cover a similar
frequency range but with remote tuning via an optical fibre link, under the control of software
which also controls an EMC measuring receiver. The third type is a larger (1.6 m diameter)
tuned loop covering 1.75 - 10 MHz that allows the measuring system noise floor to be below
the typical atmospheric noise floor. The fourth type is an electrically short dipole covering 10 -
30 MHz with improved matching.
The protection requirements for various types of radio communication services are analysed
and are compared with emission levels from various types of wireline communication network.
A review of existing applicable EMC standards and standards under development is also
presented.