Attenuation and Q-factors in waveguides

Shows how the definitions of the attenuation and Q-factors for coaxial lines and resonant circuits can be generalized to obtain attenuation per unit length for each wave structure propagated at a definite velocity in a waveguide, and the Q-factor for a section of guide used as a resonant cavity. A fundamental relation between these two factors, derived earlier [Abstr. 1946B01332] permits the determination of the attenuation per unit length by measurement of the Q-factor and of the energy transfer velocity, the latter being itself derived from the phase velocity. Attenuation can be measured by this method in the laboratory using cm-waves and guide sections only a few metres long.