The partial illumination option does not exist below 1GHz unless you have a product larger than 1.5m x 1.5m, in which case the uniform field must be a minium 1.5x1.5 size. If you choose to use a smaller uniform field below 1GHz, then the EUT must reside fully within the uniform field dimensions. (Section 6.2, table 2). Above 1GHz this limitation does not exist, partial illumination with a smaller UF is allowed. There are some other subtle differences in the standard regarding <1GHz and >1GHz as well, such as the 3% of frequencies can be above 6dB but below 10dB allowance, below 1GHz. As far as tricks/tweeks, it depends on the particular problem and the frequency where the problem occurs. If absorber performance or chamber size (small) is a problem, moving the antenna closer to the UF will help as long as the beamwidth is not an issue (usually not too much of an issue with a biconilog antenna). The further the antenna is from the UF, the less difference between direct/indirect signal paths and the more effect reflections will have on uniformity. FWIW, we have recently been trying to get our old compact chamber to perform above 1GHz. It performed well up to 1GHz with just the ferrite tiles in place. We added different types of cones to the walls, ceiling and floor and got it to perform well above 1GHz. However, those same cones screwed up the performance below 1GHz, so we are now in the process of trying movable panels. I had been told a long time ago that the cones need to be matched to the tile, maybe that is what I am seeing, but I'm trying to work with the cones that I already have available. Bob R.
--- On Tue, 9/27/11, [email protected] <[email protected]> wrote: From: [email protected] <[email protected]> Subject: Re: [PSES] Still (more) on Radiated Immunity To: [email protected] Cc: "WNya" <[email protected]> Date: Tuesday, September 27, 2011, 10:58 AM The requirement is 75% of the points you are using. So for a UFA using 12 points, you can still eliminate 3 of the 12 points when determining if you have a uniform field. The only exception to the 75% rule is for 4 points, where all the points must be with the 6 dB variance limit BTW, there is also the option of partial illumination when the UFA does not cover the whole product. It takes multiple runs to test the product fully, but gets the job done. Donald Borowski Schweitzer Engineering Labs Pullman, WA From: WNya <[email protected] <http //us.mc11.mail.yahoo.com/mc/[email protected]> > To: Charlie Blackham <[email protected] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > Cc: "<[email protected] < ttp://us.mc11.mail.yahoo.com/mc/[email protected]> >" <[email protected] <http://us. c11.mail.yahoo.com/mc/[email protected]> > Date: 09/27/2011 07:46 AM Subject: Re: [PSES] Still on Radiated Immunity Sent by: [email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> Hi Charlie, I can, at best, eliminate the top rows. My EUT is small but it is tested as a floor standing device, mounted on a wooden structure. Does this means the FUM requirement is 75% of these 12points? Or is it 100% of these 12points? Sent from Wendy.Nya iPhone On Sep 27, 2011, at 10:18 PM, "Charlie Blackham" <[email protected] <http:// s.mc11.mail.yahoo.com/mc/[email protected]> > wrote: > Wendy > > Have you considered a smaller one? - you can use smaller UFA if EUT size > permits. > > Regards > Charlie > > -----Original Message----- > From: WNya [mailto:[email protected] <http://us.mc11.mail.yahoo.com/mc/[email protected]> ] > Sent: 27 September 2011 15:10 > To: Charlie Blackham > Cc: <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> > > Subject: Re: [PSES] Still on Radiated Immunity > > The UFA is as per the standard, 1.5x1.5m, 0.8m above GRP > > Sent from Wendy.Nya iPhone > > On Sep 27, 2011, at 9:44 PM, "Charlie Blackham" > <[email protected] <http: /us.mc11.mail.yahoo.com/mc/[email protected]> > wrote: > >> Wendy >> >> What size UFA (uniform field area) are you trying to create? >> What size are your EUT (i.e. what sixe UFA do you need?) >> >> Regards >> Charlie >> >> -----Original Message----- >> From: WNya [mailto:[email protected] <http://us.mc11.mail.yahoo.com/mc/[email protected]> ] >> Sent: 27 September 2011 14:28 >> To: [email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> >> Subject: [PSES] Still on Radiated Immunity >> >> Dear EMC Experts, >> >> I have a 4x3m chamber. I encounter much difficulty to calibrate the > chamber >> every year. I am using a Schwarzbeck 9128DS and a AR systems. >> >> Does anyone know any 'tricks' to 'tweak' the chamber to perfection? >> >> PS: PAMP is 250W, up to 1GHz. >> >> Sent from Wendy.Nya iPhone >> >> - >> ---------------------------------------------------------------- >> 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] <http://us.mc11. ail.yahoo.com/mc/[email protected]> > >> >> All emc-pstc postings are archived and searchable on the web at: >> http://product-compliance.oc.ieee.org/ >> 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] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > >> Mike Cantwell <[email protected] < ttp://us.mc11.mail.yahoo.com/mc/[email protected]> > >> >> For policy questions, send mail to: >> Jim Bacher: <[email protected] <ht p://us.mc11.mail.yahoo.com/mc/[email protected]> > >> David Heald: <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[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] <http://us.mc11.m il.yahoo.com/mc/[email protected]> > >> >> All emc-pstc postings are archived and searchable on the web at: >> http://product-compliance.oc.ieee.org/ >> 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] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > >> Mike Cantwell <[email protected] < ttp://us.mc11.mail.yahoo.com/mc/[email protected]> > >> >> For policy questions, send mail to: >> Jim Bacher: <[email protected] <ht p://us.mc11.mail.yahoo.com/mc/[email protected]> > >> David Heald: <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[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] <http://us.mc11. ail.yahoo.com/mc/[email protected]> > > > All emc-pstc postings are archived and searchable on the web at: > http://product-compliance.oc.ieee.org/ > 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] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > > Mike Cantwell <[email protected] <h tp://us.mc11.mail.yahoo.com/mc/[email protected]> > > > For policy questions, send mail to: > Jim Bacher: <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> > > David Heald: <[email protected] <http //us.mc11.mail.yahoo.com/mc/[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] <http://us.mc11.mai .yahoo.com/mc/[email protected]> > All emc-pstc postings are archived and searchable on the web at: http://product-compliance.oc.ieee.org/ 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] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > Mike Cantwell <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> > For policy questions, send mail to: Jim Bacher: <[email protected] <http: /us.mc11.mail.yahoo.com/mc/[email protected]> > David Heald: <[email protected] <http:/ us.mc11.mail.yahoo.com/mc/[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] <http://us.mc11.mail yahoo.com/mc/[email protected]> > All emc-pstc postings are archived and searchable on the web at: http://product-compliance.oc.ieee.org/ 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] <http://us.mc11.mail.yahoo.com/mc/[email protected]> > Mike Cantwell <[email protected] <htt ://us.mc11.mail.yahoo.com/mc/[email protected]> > For policy questions, send mail to: Jim Bacher: <[email protected] <http: /us.mc11.mail.yahoo.com/mc/[email protected]> > David Heald: <[email protected] <http:/ us.mc11.mail.yahoo.com/mc/[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://product-compliance.oc.ieee.org/ 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]>
