How to retrieve effective parameters for metamaterials.
I found it was not right from Smith's method [D. R. Smith, D. C. Vier, Th. Koschny, and C. M. Soukoulis,Phys. Rev. E 71, 036617 2005].
For in-plane incidence, it may be correct. But out-off plane, you may think about other methods. Also please see the previous discussions on this topics.