hfss permittivity
you can calculate the real and imaginary parts of permittivity/permeability in matlab using your drude/lorentz whatever model. and then you need to calculate the tangent delta electric/magnetic using these real and imaginary parts. you need to write these parameters in a data file in matlab, like: frequency - real(eps) and another file frequency - tand(eps).
now, in hfss, you will open your material properties, and select frequency dependent. you will import these data files. that's it!
make sure you use exp(jwt) time dependence (hfss uses this). therefore:
eps = eps_r - j *eps_im
tand_e = eps_im/eps_r
same for permeability.
and also make sure you use frequency in Hertz in the data file. e.g., for 1GHz you need to enter 1e9.
take a look at the hfss help files for freq dependent material properties.
hope this helps...