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.

Meeting Name

IEEE International Symposium on Electromagnetic Compatibility, 2002


Electrical and Computer Engineering

Keywords and Phrases

1 to 20 GHz; FDTD; Differential Signal Behavior; Differential Signals; Engineering Estimation; Equivalent Circuit Methods; Equivalent Circuits; Finite Difference Time-Domain Analysis; Mixed-Mode S-Parameters; Transmission Line Theory; Transmission-Line Reasoning; Vias Transmission Line Modeling

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2002 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.