On the Accuracy of the Parameters Extracted FromS-Parameter Measurements Taken on Differential IC Transmission Lines

In this paper, we compare the accuracy of the telegrapher's equation transmission line parameters extracted with different methods from deembeddedS-parameter measurements taken on differential integrated circuit transmission lines. We present a mathematical proof that conventional "open-short" deembedding is sufficient to extract the intrinsic propagation constantgamma of the transmission line, but that at the same time, some deembedding errors will remain for the extracted characteristic impedance Z_{0}. We illustrate this by comparing experimental results obtained after "open-short" and "short-open" deembedding, and explain that as a result of this, using either known capacitance/known conductance or known inductance/known resistance approximations to study the remaining transmission line parameters can be attractive.