Is DC Power Transmitted by Electromagnetic Waves?

A 5-MHz sinusoidal signal, a 500-Hz sinusoidal signal, and a DC signal are compared among each other experimentally when they are turned on, after they are established over a piece of long co-axial cable, and when they are turned off. The experimental results do not demonstrate any fundamental differences among the 5-MHz signal, 500-Hz signal, and DC signal in terms of propagation over the co-axial cable. Based on the experimental results, the well-known formulations of AC wave propagation are extended to DC wave propagation. The experimental and theoretical studies of this paper indicate that DC electrical power is transported by electromagnetic wave propagation in practical DC circuits.