The Variation of the Attenuation Constant of Low-Loss Transmission Lines in the Presence of Standing Waves

A mathematical description of the variation of the attenuation constant in the presence of standing waves is presented. This letter proposes equations describing such phenomena, formulated from basic transmission line analysis. The results could be used to correct errors in precision microwave measurements. Both dielectric and resistive losses are considered, followed by a study of frequency dependence. Practical results of fabricated microstrip lines are presented with comparison to the derived theory.