A semi-empirical approach for predicting the performance of multiphase composites at microwave frequencies

We predict the fraction of incoming electromagnetic signals reflected (R), transmitted (T), and absorbed (A) by multiphase composites containing combinations of stainless steel spheres and flakes at microwave frequencies by adapting a semi-empirical method. Using single inclusion fitting exponents, we fit expressions for R, T, and A for each loading combination to determine the parameter A
_x
and the host's fitting exponent. The host exponent is constant for all composites while A
_x
varies linearly with the inverse of total inclusion volume loading (v
_tot
) for a given flake loading (v
_f
). The insensitivity of A
_x
to Vf at a given v
_tot
indicates that the volume loading of spheres, which is generally higher than that of the flakes in the studied composites, drives effective behavior.