An excellent question! I can't say conclusively but this is gut feel. In a reverb chamber any metallic ground plane acts as a boundary and in the immediate vicinity an EM wave polarized parallel to that surface will be attenuated. Hence the restriction you noted. But the attenuation near the plane to which the EUT is bonded is allowed to attenuate horizontal polarization - because that is expected in the actual installation. That is also why the field sensors for RS103 are mounted 30 cm above the ground plane, to allow for the natural attenuation of horizontally polarized waves near the ground plane. So I would say that cable layout for a reverb chamber test should be no different than in anechoic chamber. And for a reverb chamber in particular, I would say that ground plane size has no effect, the field would not be diminished more in the center than near the edges. It may well be that cable rf pick-up efficiency is diminished relative to those within 10 cm of the edge, but that effect would be even more pronounced in a traditional test where the field would diminish in intensity as you moved further and further back from the transmit antenna.
---------- >From: "Ken Javor" <[email protected]> >To: [email protected] >Subject: reverb chamber test set up question >Date: Sat, Dec 16, 2000, 8:30 PM > > Dear Colleagues, > > MIL-STD-461 requires cables to be laid out within 10 cm of the front edge of > the ground plane, which standardizes both RE efficiency and RS coupling. > How about for a reverb test? Is it as important for cables to be near the > ground plane edge, or can they be routed anywhere? Corollary: In a reverb > chamber EUT is not placed near wall as per -461, it is placed away from wall > to guarantee that max field intensities will develop in its vicinity. What > is effect of large ground plane (one twice the mil-std ground plane depth > or more)? Does this diminish field significantly around itself? > > Thank you. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [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: No longer online until our new server is brought online and the old messages are imported into the new server.
