Details

Snapshot 1: an electric field distribution

Snapshot 2: a magnetic field distributions

Snapshot 3: a Poynting vector distribution

The electric field of parallel cylinders is calculated assuming parallel line charges with separation , where and are the gap length and cylinder diameter. The magnetic field is simulated by that of parallel line currents flowing along the cylinder axes (i.e. a uniform current density is assumed, ignoring the skin effect). The electric and magnetic vectors are in the plane of observation perpendicular to the cylinders. The average of the Poynting vector, given by , is directed along the axial direction of conductors.

The electric and magnetic field intensities (shown in colors for the peak values) are similarly distributed on the observation plane, but the directions are very nearly mutually perpendicular. The Poynting vector's intensity distribution in space decreases rapidly with the distance from the conductor.

The power of the transmission line is actually carried in a thin region on the outside of the conductors, not within the lines themselves.

Reference

[1] J. A. Stratton, Electromagnetic Theory, New York: McGraw–Hill, 1941.