I haven't been dealing with chambers recently, so I don't have the freshest contact info, but there are manufacturers of the chambers and absorbers who can help you modeling it. TDK and Siemens were doing it long time ago, I guess many more have joined meanwhile. Just adding absobers over the tiles can hurt you (typically in some frequency bands), depending on many factors. It is probably the best to contact the vendor of your chamber/absorbers Also, at 1.5 GHz you may have considerable free-space attenuation, so have you considered having the line between the DUT and the antenna not aligned with the chamber walls (flooor and ceiling including) in order to create longer paths for the reflected waves, which could reduce the influence of the reflections? Neven
-------------- Original message -------------- From: "Kealey, Doug" <[email protected]> > Group, > > We are a manufacturer and 4 of our chambers are used largely for FCC > pre-scanning. They are 10' x 10' x 23' lined with ferrite tile on walls and > ceiling. There are sections of ferrite cones on top of the ferrite tiles on > portions of the sides and the end wall. > > We want to further reduce reflections in the chambers at 1.575 GHz for some > sensitive GPS receiver testing. [We put panels of ferrite cones on the > floor for this kind of work.] So our 1st thought is to add more cones (ones > that are effective at > 1GHz) on the surfaces where there is currently just > ferrite tile. > > Is there enough of a possibility that we would inadvertently degrade our NSA >! ; curves or our field uniformity, that we might want to have somebody model > this idea before we jump into it? If you have a recommendation as to who to > hire for this, please email me off-line. > > Thanks for your thoughts. > > Best regards, > Doug > > Doug Kealey > Garmin International Inc. > Olathe, KS > > 913-440-5210 > [email protected] > > > > ------------------------- > This e-mail and any attachments may contain confidential material for the sole > use of the intended recipient. If you are not the intended recipient, please be > aware that any disclosure, copying, distribution or use of this e-mail or any > attachment is prohibited. If you have received this e-mail in error, please > contact the sender and delete all copies. > Thank you for your cooperation > ! > - > ------------------------------------------------------ ---------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > 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] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
