ABSTRACT
This chapter discusses the techniques for the wideband measurement of attenuation and dispersion of signals propagating through walls. Dispersion theories predict that, away from the resonance regions, the dielectric constant of a material increases with frequency. In fact, it has been shown that the dispersion curves of most materials follow a few well-known classical models, such as Debye and Lorentz models. Time gating is required to remove multipath components from the received signal resulting from surrounding walls and scattered fields from sample edges, as they are not accounted for in the calculation and extraction of the material parameters in a single-pass model. The results of the loss of tested materials are used to develop the frequency-dependent through-the-wall propagation model. The determination of the electrical properties of the wall materials is essential, as these properties affect a variety of applications including through-the-wall imaging.
