On Thu, 5 Aug 2010 20:18:11 -0700 (PDT), Bob Richards <b...@toprudder.com> wrote:
> >>>Is there any special equipment needed? I have two of 3117 horn antenna > and an Agilent N5182A in my workplace.<<< > > I have not done this procedure yet, but have read up on it some. I > don't have a copy of the standard handy right now, but I believe one > of the antennas (the one moved around the turntable) must be > isotropic. A horn is not suitable. The reason, as I understand it, is > that a horn will give results that do not test the back-wall absorber > since it has a high front-back ratio. Someone correct me if I am > wrong. (ducking for cover.....) :-) Well, the transmitting antenna must a near-omnidirectional antenna which have beam pattern specified in CISPR 16-1-4. Example of such antennas are: Schwarzbeck SBA9113 & SBA9112 Seibersdorf Laboratories POD16 As Mr Richards says, reflections from back wall, and also that >from side walls and floor and ceiling, may not be evaluated enough if we use highly directional antennas for transmission. I think the standard specifies required beam pattern to avoid this problem, although the standard permit antennas which have null backward, as we can see in the standard and, for example, also in http://www.schwarzbeck.com/Datenblatt/RI9112H.pdf. Receiving antenna should one that will be used for measurement on the site, I guess that is 3117 in this case. However, 3117 has relatively wide beamwidth at low frequencies and maybe make it slightly difficult to achieve low SVSWR. Regards, Tom -- Tomonori Sato <vef00...@nifty.ne.jp> URL: http://homepage3.nifty.com/tsato/ - 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 <emc-p...@ieee.org> 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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
