I don't have that spec but offer a different interpretation than you have chosen. "Parallel to the line-of-sight" to me means in the direction of the traveling wave emanating from the antenna, i.e. in the direction of the Poynting vector.
I can't say why they chose this orientation, but under a perfectly matched and loaded strip line the Poynting vector is replaced by the flow of energy >from source to load in a manner perfectly simulating a traveling plane wave. It is typical under such a line that the cables attached to the EUT are aligned parallel to the flow of energy. If you look at the positions of the electric and magnetic field vectors relative to the cables, it is clear that that test topology causes maximum coupling to the cables-under-test. The actual orientation of the EUT relative to these vectors is in my opinion not nearly as important, because at the frequencies you use the typical strip-line, coupling is mainly to the cables, not the EUT internal circuitry. Again I state I am not familiar with the specifics of the specs you cite, this is just general electromagnetic theory applied to radiated immunity testing under a plate. Ken Javor > From: ??? <[email protected]> > Reply-To: [email protected] > Date: Thu, 14 Oct 2004 02:28:53 +0000 (GMT) > To: [email protected] > Subject: Field immunity test for DUT not fitting in the open strip > > Dear All, > > According to CISPR or EN55020, field immunity for large equipment not fitting > in the open strip line > shall be measured based on the following setup: > > "The front side of the EUT shall be positioned parallel to the antenna line of > sight." > > This measurement setup is shown in Section 5.8.4, p.39, EN55020:2002 and > Section 5.8.4, p.77, CISPR20:2002. > > Can anyone let me know in detail how to setup the position of the EUT parallel > to the antenna? > Any comment will be appreciated. > > Thank you, > > > -SEOL BYONG SU > Samsung Advanced Institute of Technology > > ---------------------------------------------------------------- > 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/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Ron Pickard: [email protected] > Scott Douglas [email protected] > > For policy questions, send mail to: > > Richard Nute: [email protected] > Jim Bacher: [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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
