Transmission-Line Analogies of Plane Electromagnetic-Wave Reflections

The similarity between the equations for unguided plane electromagnetic-wave propagation and those of propagation along conventional transmission lines is illustrated here. It is shown that the conventional transmission-line equations expressed in terms of receiving-end voltage and current may be used to express the field-intensity components of uniform plane waves in any medium. Normal-incidence reflection of plane waves at surfaces of discontinuity are shown to be analogous to transmission-line reflections at impedance discontinuities. The transmission-line equations are then modified to apply to oblique incidence reflection. The relationships developed here assist in visualizing as well as solving plane-wave propagation and reflection problems using the conventional transmission-line equations. It also makes possible the use of transmission-line charts for the solution of wave-reflection problems.