On Single-Wire Power Line Microwave Communication Using Low-Loss Modes

Using only the thin-wire approximation, a closed-form solution for the current induced on an infinitely long conductor by a voltage source or an electric dipole in close proximity was found. For lossy conductors, the current consists of a continuous spectrum of radiation modes and a low-loss discrete mode, the Sommerfeld-Goubau (SG) mode. While the relative magnitude of these two components is sensitive to frequency and wire conductivity, the total current is nearly the same as for a perfect conductor over distances comparable to power line communication repeater spacing. For observation points not near the source, the current induced by the voltage and dipole sources differs only by a known constant. Hence, it is possible to use total current expressions from antenna theory to evaluate the performance of power line communication systems. These are used to show the advantage of a single-conductor communication channel to that of a wireless channel using high-gain antennas.