SURFACE-WAVE TRANSMISSION LINE
a. General. The surface-wave transmission line (SWTL) is a new type of low-loss transmission line.
It uses a single, dielectric-coated conductor as a means of wave conduction. The SWTL solves the
problem of reducing the radiation loss so that the line will not act as a long-wire antenna. The
nonradiating-wave mode is brought about by the resistivity of the wire. A perfectly conducting wire
could not guide a nonradiating wave. The SWTL causes a reduction in the phase velocity of the radio
energy field, as compared with the free-space velocity.
This reduction in phase velocity is