How the surfaces in the anechoic chamber provides perfect match to the signals?

How the surfaces in the anechoic chamber provides perfect match to the signals(i.e completely absorbing)..with what material they r made of?

For emc: ferrite.

The cones you see in a chamber are usually a urethane foam impregnated with carbon so that waves are attenuated. The lowest frequency of operation is where the cones are on the order of a wavelength or two.


Look for more information with companies like Rantec, Advanced Electromagnetics, Cumming, and the like.

my apology, if there someone know how to design an anechoic chamber? I'm currently designing an anechoic chamber with the material made from foam and ferrit but it difficult to design the chamber. i need some reference related to anechoic chamber. thanx.

BR,
Erik Ng

Call advanced Electromagnetics and ask for Gabe Sanchez. He may be willing to provide guidance.

look at this books and papers

http://eu.wiley.com/WileyCDA/WileyTi...471208108.html
http://www.sae.org/technical/papers/1999-01-1832
http://www.ingentaconnect.com/conten...9?crawler=true
http://cat.inist.fr/?aModele=afficheN&cpsidt=15484936
http://ieeexplore.ieee.org/xpl/freea...rnumber=117905

pl

thanks for your reply. i check the link, and find that all of it must purchase the paper. but i already have some books from the links.
i try to find some related papers for free but find zero, so maybe i must design it from wiley book only.