Computation of Intra-pair Skew for Imbalance Differential Line using Modified Mixed-mode S-parameter

Abstract

We proposed the computation method of the intra-pair skew for an imbalance differential line using the modified mixed-mode S-parameter. Since the intra-pair skew is caused by the difference of arriving time at each trace when the differential-mode signal is sent through the differential line, it is hard to calculate the intra-pair skew in differential-mode by using the standard s-parameter or mixed-mode s-parameter. The modified mixed-mode s-parameter can represent the relation between differentia-mode incident wave and output wave of each trace. Consequently, we can obtain the accurate intra-pair skew using the modified mixed-mode s-parameter at frequency-domain. The proposed computation method has been verified by the time-domain and frequency-domain simulations for imbalance transmission line.