Fundamental EMI source mechanisms leading to common-mode radiation from printed circuit boards with attached cables are presented in this paper. Two primary EMI source mechanisms have been identified: one associated with a differential-mode voltage and another associated with a differential-mode current, both of which result in a common-mode current on an attached cable. These mechanisms can be used to relate printed circuit layout geometries to EMI sources. The two mechanisms are demonstrated through numerical and experimental results, and an example from a production printed-circuit design is presented.


Electrical and Computer Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory


General Motors Corporation
National Science Foundation (U.S.)


This work was supported in part by General Motors and the National Science Foundation through a graduate research fellowship.

Keywords and Phrases

Attached Cables; Common-Mode Current; Common-Mode Radiation; Differential-Mode Current; Differential-Mode Voltage; Electromagnetic Interference; Fundamental EMI Source Mechanisms; Printed Circuit Boards; Printed Circuit Layout; Printed Circuit Layout Geometries; Production Printed-Circuit Design; Coaxial Cables; Integrated Circuit Layout; Mathematical Models; Printed Circuit Design; Electromagnetic Interference Mechanisms; Electromagnetic Wave Interference

International Standard Serial Number (ISSN)

0018-9375; 1558-187X

Document Type

Article - Journal

Document Version

Final Version

File Type





© 1996 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Nov 1996