Mark Looking at the 2006 standard, the reference to "sensitive frequencies" is "The sensitive frequencies (e.g. clock frequencies) shall be analysed separately according to the requirements in product standards"
AFAIK there's no reference to this in product standards (certainly never come across it in EN55024 and EN301 489-x) Spot frequency tests are called up in standards such as EN55024 - but even then it calls up 80% AM modulation for frequencies such as 900 MHz - which is of limited use as GSM interference is better simulated using pulsed interferer. The EMC directive requires you to consider your product and its EM environment so you may need to develop specific tests for it - but labs are accredited to test to standards which can't cover all eventualities. Regards Charlie From: Mark Gandler [mailto:[email protected]] Sent: 03 February 2012 00:48 To: [email protected] Subject: [PSES] IEC61000-4-3: sensitive frequencies Group, what are the current test lab practices to evaluate "sensitive frequencies" as specified in 61000-4-3? It is fair to assume what some of the "sensitive frequencies" will be missed with 1% step, especially in higher range. Some of the big telco's have dedicated procedures on how to treat sensitive or frequencies of key interest ("foki") with dedicated levels, dwell times, 50kHz steps and so on. But it feels like an uphill battle to convince the labs and to explain the procedure, which brings up the suspicion what there are not much of "sensitive frequencies" evaluations going on. This fits in ongoing discussion about field uniformity and calibration procedures. If you need to investigate individual frequencies, you should calibrate the field at these frequencies. How about 'external' frequencies sources, such as LTE or any other mobile communications? should they not be tested separately or just hope they get addressed during the sweep? Any opinions on test methodologies, besides traditional sweep are welcome. Thanks, Mark Gandler Netgear - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]<mailto:[email protected]>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
