Hello, I would like to design a pyramidal electromagnetic absorber for use in an anechoic chamber. In this type of absorber, the material properties are very important. Does CST Studio Suite  provide any predefined absorber materials? From what I’ve seen, I couldn’t find any, and it seems like I have to define the material properties manually. Is that the only option?

When comparing the use of the T-solver and the F-solver to check the return loss, the matching frequency at which S11 = -20 dB starts is almost the same. However, after that point, there begins to be a slight difference in the results. Aside from the difference in meshing methods, could there be any other reasons for this? Additionally, can we say that one is more accurate than the other?

Thank you!