Design of Low-loss Transmission Lines with Common Mode Suppression for Packages

Durgun A. C., Aygun K.

27th IEEE Conference on Electrical Performance on Electronic Packaging and Systems (EPEPS), San-Jose, Costa Rica, 14 - 17 October 2018, pp.43-45 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • Doi Number: 10.1109/epeps.2018.8534202
  • City: San-Jose
  • Country: Costa Rica
  • Page Numbers: pp.43-45
  • Keywords: low-loss transmission line, common mode filter, high-speed interfaces, periodic structures, FILTER
  • Middle East Technical University Affiliated: No


Increasing data rates of high speed serial interfaces forces the insertion loss and common mode (CM) noise requirements to be tighter. This paper addresses both of these challenges by introducing a new low-loss transmission line design with simultaneous common mode filtering property. The line is composed of periodical repetitions of narrow and wide sections, which generates a CM impedance contrast to filter out the CM noise, while differential impedance is kept constant by locally voiding the planes below and above the wide trace sections. As a result of the wider sections, the loss is also smaller.