An assessment on the accuracy of time-domain reflectometry for measuring the characteristic impedance of transmission lines

Abstract

An assessment of time-domain reflectometry (TDR) for measuring the characteristic impedance Z/sub TL/ of transmission lines is performed. The assessment includes the accuracy of measuring ZTL as a function of TDR electrical impedance Z/sub o/, the ability to measure impedance perturbations as a function Of ZTL and Z/sub o/, and the ability to differentiate between transmission lines of similar ZTL. The information presented will be especially useful for those using 50 /spl Omega/ TDR systems to characterize transmission lines having characteristic impedances less than about 30 /spl Omega/.