Transmission Line Modeling of Vias in Differential Signals

James L. Drewniak, Missouri University of Science and Technology
Ray Alexander
Norman W. Smith
Chen Wang
Jun Fan, Missouri University of Science and Technology
James L. Knighten

This document has been relocated to http://scholarsmine.mst.edu/ele_comeng_facwork/1923

There were 10 downloads as of 28 Jun 2016.

Abstract

Signal layer transitions in differential lines are modeled using both FDTD and equivalent circuit methods. The equivalent circuit is developed based on transmission-line reasoning regarding via behavior. Parameters of each transmission-line segment are obtained based on its corresponding physical geometry. The mixed-mode S-parameters from the equivalent circuit and the FDTD modeling are compared. Good agreement is demonstrated in the frequency range from 1 GHz to 20 GHz. The results indicate that vias in differential lines can be modeled as a transmission line for a quick and easy engineering estimation of the differential signal behavior in an environment of signal layer transitions.