Investigation of Mixed-Mode Input Impedance of Multi-Layer Differential Vias for Impedance Matching with Traces


In multilayer printed circuit boards (PCBs), vias are commonly used to connect traces on different signal layers. This paper derives the mixed-mode input impedance of differential vias in typical multilayer structures, and proposes to use the input impedance concept to achieve impedance matching at the via and trace connections. Effects of several geometrical parameters on the input impedance of differential vias have also been studied in this paper. This method can be used to optimize via structures in PCB design processes for smooth via-trace transitions.

Meeting Name

IEEE International Symposium on Electromagnetic Compatibility (2009: Aug. 17-21, Austin, TX)


Electrical and Computer Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory

Keywords and Phrases

Differential Via; Impedance Matchings; Input Impedance; Mixed Mode; Signal Integrity; Electric Impedance Measurement; Electromagnetic Compatibility; Impedance Matching (Electric); Multilayers; Plastic Molds; Printed Circuit Manufacture; Printed Circuit Boards; Impedance Matching; Mixed-Mode Input Impedance; Via-Trace Transition

International Standard Book Number (ISBN)

978-1424442676; 978-1424442669

International Standard Serial Number (ISSN)

2158-110X; 2158-1118

Document Type

Article - Conference proceedings

Document Version


File Type





© 2009 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

21 Aug 2009