Power transmitted by a medium of complex wave impedance

The paper discusses the part played by a reactive component of wave impedance in providing for a proportion of the power transmitted under standing-wave conditions. In particular, attention is called to microwave propagation in a lossy medium, such as a semiconductor, in an ionised gas and in a waveguide operated near cutoff. It is shown that, in each of these cases, the storage fields of oppositely directed travelling waves may interact significantly to produce a net flow of power differing appreciably from what is indicated by the resistive component of the wave impedance. Measurements of power transmitted in a medium of complex wave impedance therefore cannot always be obtained accurately in terms of the difference between the powers carried separately by oppositely directed waves at the point considered.