All, I'm fishing for some comments and/or recommendations regarding configuring our test site to measure radiated emissions above 1GHz per EN55022:2006 +A1:2007.
My question isn't really the base requirements of the standards so much as how to implement it in our test site. For radiated emissions measurements we use a 10m Semi-anechoic chamber with a 10m turntable. We routinely fill the table. The typical product that would fill the turntable is ~9.5m X 2m. For FCC testing >1GHz there is no issues, the beam-width of the antenna is wide enough at 10m we can perform testing in a "similar" fashion as it's done below <1GHz. The emissions requirements from EN55022 and CISPR 16 state that the preferred measurement distance is 3m; however, CISPR 16-2-3 allows for other test distances. For implementation, we would either have to fill the remaining 2/3 of the turntable with absorber (or at the very least the front or rear of the EUT) plus the distance from the turntable edge to the antenna. OR, perform the measurement at a 3m distance and move the antenna mast in segments equal to the beam-width (or half power beamwidth) of the antenna. My problem: The quote for just the absorber at a 3m distance was significant. So increasing the absorber to cover 10m plus covering enough of the turntable to make it usable is going to cost 5X (just a guess on my part). In my experience testing above 1GHz, emissions can be very sensitive with regard to EUT angle. If the EUT remained stationary, then for each beam width position laterally across the span of the EUT you would have to manually adjust the yaw(??) of the antenna across the range of that beam width position (as well as vary the antenna height / bore sight). This would seem to be subject to errors of repeatability. Any comments or is there something obvious I'm missing? Thanks Best Regards David Spencer EMC Engineer Xerox Corp - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]>
