The question is quite self-explanatory. What word can be used to describe something that blocks radio waves?
Edit: No, I am not looking for some easy word like "block" or "blocker". This is part of a project, and I need a word that sounds sophisticated.
Edit 2: Sentence example:
_______ has a high attenuation coefficient.
I went to this website looking for an answer. I didn't find one... However, it explains what radio waves are pretty well, though.
https://www.scientificamerican.com/article/bring-science-home-block-radio-waves/
Thanks!