Mr. Honkala violates the fundamental rule of physics annunciated by Albert Einstein: "Everything should be made as simple as possible, but not simpler."
While the antenna factor is by definition the ratio of voltage delivered at the antenna terminal relative to illuminating electric field, it is the nature of the illuminating electric field itself which is different between three, ten, thirty meters and free space. Free space implies a plane wave illumination, the other separations more or less approximate free space illumination according to frequency and antenna geometry, because antenna factor is measured using two identical antennas a fixed distance apart. The three, ten or thirty meter antenna factor approaches the free space factor when the antenna physical size is small with respect to separation, making it look like the point source radiator of a plane wave. Ken Javor Phone: (256) 650-5261 > From: <ari.honk...@nsn.com> > Date: Fri, 29 Feb 2008 09:59:58 +0200 > To: <emc-p...@ieee.org> > Conversation: Free Space Antenna Factor > Subject: RE: Free Space Antenna Factor > > Back to basics: > Antenna factor is merely the ratio of E-field strength and the voltage in > antenna terminals. > Therefore it is not related to any distance from source. > > It is related to distance from ground plane, but the free-space AF gives a > practical average value that is usable when a single figure is used in > emission test. > > Determination of AF in different ways means different errors in it. > > Ari > >> -----Original Message----- >> From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf >> Of ext John Woodgate >> Sent: 29. helmikuuta 2008 9:44 >> To: emc-p...@ieee.org >> Subject: Re: Free Space Antenna Factor >> >> In message >> <e2ceff6b0970a840bb7597dc31bec33003100...@esebe107.noe.nokia.co > m>, dated >> Fri, 29 Feb 2008, ari.honk...@nsn.com writes: >> >>> read the appendix 3 of the NPL paper. >>> They state that " free-space antenna factor is appropriate for 3 m >>> measurements". >> >> What is the context? I think it's a surprising statement if it is said >> to be applicable to all possible designs of antenna. >> -- >> OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk >> For very important information, please turn over. >> John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK >> >> - >> ---------------------------------------------------------------- >> 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: emc-p...@daveheald.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: emc-p...@daveheald.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: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
