The noise in the 10 MHz - 30 MHz range in modern switched-mode power supplies originates in parasitic resonant (tank) circuits that are rung (excited) by the fast rise and fall times of the pulses in the power supplies. The ringing is then coupled, both by radiation and conduction, into the input circuits and out to your measurement system, unfortunately!
Here are a couple of good references. 1. Virginia Tech in Blacksburg, VA has a good Web site and one of the largest post-graduate programs in power electronics. It is the headquarters of the 5-university consortium, the Center for Power Electronics Systems. Go to www.vt.edu, then put EMI in the search window. It retrieved 470 references for me in 0.11 seconds. The first paper, and many others are excellent. You can download what you need. 2. Jerrold Foutz has a Web site of a broad range of power supply subjects. Visit www.smpstech.com. IEEE Power Electronics Society is also, obviously, a good source. Many EMI papers have been presented at the IEEE sponsored conferences on the subject: APEC, Intelec, and PESC. You can dig your way through these on the Web site, www.ieee.org. Best ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
