I agree with Mike that having variable materials and geometries in the signal path an be problematic I have had difficulty with this in the past as well. Respectfully, Brent DeWitt Vancouver, WA
________________________________ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Michael Heckrotte Sent: Thursday, October 16, 2008 3:31 PM To: codymil...@micron.com; emc-p...@ieee.org Cc: emcp...@aol.com; emc-p...@ieee.org Subject: RE: OATs enclosure interference Cody, Many years ago I did an NSA measurement on an OATS that had a (large room-size, not tent-size) rectangular fiberglass enclosure over the turntable. There was a personnel door between the turntable and the antenna. With this door open, the difference in dielectric constant between the fiberglass and air, combined with the width of the doorway, created a diffraction pattern that caused the NSA to go out of spec. Closing the door solved the issue. Looking at your picture, the door appears to be wider, but there could be similar problems if it was partially open. The spherical structure compared to rectangular could make some difference as well. Nevertheless, you could easily experience the same phenomena, so locating the door to the side is likely to give you better results. Best Regards, Mike Michael Heckrotte Director of Engineering Compliance Certification Services 47173 Benicia Street, Fremont, CA 94538 Main: (510) 771-1000 Direct: (510) 771-1121 Fax: (510) 661-0885 michael.heckro...@ccsemc.com ________________________________ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of codymil...@micron.com Sent: Thursday, October 16, 2008 2:56 PM To: emc-p...@ieee.org Subject: OATs enclosure interference Hi all, We are in the process of building an OATS and we have a building/enclosure that is made of fiberglass. A link to the enclosure link can be seen below. My question is does the door opening to the dome need to be facing the antenna mast while tests are running so that there is no fiberglass between the DUT and the antenna. If we could we would like the door facing the control room so we can see the turntable. Any thoughts would be appreciated. Thanks, Cody http://www.mekco.com/open_area_test_site.htm - 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 emc-p...@ieee.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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com 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 emc-p...@ieee.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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com 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 emc-p...@ieee.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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
