ABSTRACT
The simplest illustration of electromagnetic-wave propagation is the hypothetical one of sinusoidal plane waves of infinite extent in a homogeneous, charge-free medium. An elementary situation involving a nonhomogeneous region for the waves is that of two uniform media of semi-infinite extent, with a planar boundary between them. Plane waves are defined as waves that are uniform in direction and magnitude in planes of a stated orientation. Whether a given conductivity is "high" or "low" in wave-propagation, problems may be a relative matter with respect to frequency. If the electromagnetic waves are plane and uniform, and the direction of propagation is normal to the plane of the boundary surface, the result proves to be analogous to the reflections on a terminated transmission line. Metallic conducting surfaces are used abundantly to guide traveling electromagnetic fields. A quasi- transverse-electromagnetic (TEM) mode may propagate between two parallel planes of highly conducting metal.
