PCB structures for common mode suppression on differential microstrip lines

Qian Liu, Shuai Xu, David Pommerenke

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


Common mode noise on differential microstrip lines can be suppressed by PCB embedded filters. These filters are basically resonators, and only the common mode signal can couple to them. Though such structure suppress common mode signal only in narrow bands because of the resonant nature, they can be combined to produce broadband filtering effect. The dimension of such filters could be further reduced by adding lumped elements. In this paper, design principles of the PCB filters are given, and examples are given to demonstrate these rules. At last, a new PCB filter structure is proposed with an electrical size of only 0.04λ×0.067λ which is capable of suppressing the higher order harmonics of common mode signal.

Original languageEnglish
Title of host publication2014 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Number of pages5
Publication statusPublished - 15 Sept 2014
Externally publishedYes
Event2014 IEEE International Symposium on Electromagnetic Compatibility: EMC 2014 - Raleigh, United States
Duration: 3 Aug 20148 Aug 2014


Conference2014 IEEE International Symposium on Electromagnetic Compatibility
Country/TerritoryUnited States


  • Common mode filter
  • differential signal
  • lower resonant frequency
  • quarter-wavelength

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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