Muriel, I did find the reference citation that I was missing in my previous posting.
D. Hockanson, J. Drewniak, T. Hubing, T, Van Doren, F. Sha, and M. Wilhelm, "Investigation of Fundamental EMI Source Mechanisms Driving Common-Mode Radiation from Printed Circuit Boards with Attached Cables," IEEE Transactions on Electromagnetic Compatibility, Vol. 38, No, 4, November 1996, pp. 557-566, This journal article describes two mechanisms that are related to geometrical asymmetries in PCB circuits, along with parasitics, that drive common-mode currents on PCB ground planes. Neither of these mechanisms can be deduced from a circuit schematic. Good Luck, Jim Knighten ________________________________________________________ Dr. Jim Knighten e-mail: [email protected] <[email protected]> Technical Consultant - Design NCR 17095 Via del Campo San Diego, CA 92127 http://www.ncr.com <http://www.ncr.com> Tel: 858-485-2537 Fax: 858-485-3788 -----Original Message----- From: Muriel Bittencourt de Liz [mailto:[email protected]] Sent: Thursday, May 04, 2000 8:13 AM To: EMC-PSTC List Subject: Re: origin of common-mode currents Group, Thanks for all the answers to the question of common-mode emissions. But, as I did once, most of you didn't understand what I meant. I've already read books of EMC (like C.R. Paul), saw a lot of homepages/magazines (RBItem, chapters of IEEE EMC society), read books of electronics-area... etc... But all this references did not mention anything about the physical phenomena of the common-mode emissions. I don't know if I'm not being clear... So, please question me about more details... For example, in a simple circuit (a DC battery feeding a resistor), do I have common-mode emissions? Are the common-mode emissions inherent from any physical system? Can I model them in HF? Thanks in advance. Muriel ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
