Abstract
The Channel Frequency Response (CFR) is
essential in the understanding and specification of Power Line
Communications (PLC) equipment. In this paper a 10m indoor
low voltage Flat Twin and Earth power cable is characterized up
to 1GHz. This is higher in frequency than existing PLC
specifications. This is done because the effect of frequencies in the
upper VHF and lower UHF bands on PLC is largely unknown.
Measurements and simulation are used to show that at higher
frequencies, the traditional transmission line models of wave
propagation on a power line are no longer valid. Classic
attenuation models do not predict the correct CFR above typically
250MHz for a 10m cable. This effect is explained in terms of
electromagnetic radiation from the cable. After 500MHz it is
speculated that the line becomes a waveguide. These transmission
modes have important implications for UHF PLC, either directly
(connected cable) or when used in contactless mode where the
power line is used as antenna.