Ultra-wideband characterization of obstructed propagation

Ultra-Wideband (UWB) signaling is finding many applications in through-wall imaging, target positioning, and indoor communications. In this context, signal propagation through walls has to be modeled accurately since the different building materials have varying attenuation and dispersion properties that impact UWB signal propagation. One of the interesting properties of a UWB signal is its ability to penetrate walls and obstacles which comes from the lower frequency components of the signal. However, as the signal propagates through these obstacles, it gets attenuated, slows down, and gets dispersed. In this paper, we present experimental results on the frequency-domain measurements of UWB signal transmission and reflection over a frequency range of 1-18 GHz. The results presented give a thorough characterization of UWB wave propagation through walls made of common building materials (including glass, wood and gypsum). This is done by measuring the insertion transfer function given as the ratio of two signals measured in presence and absence of walls. The materials' dielectric constant and propagation loss are extracted from the measured insertion transfer function. Double layer walls and three layer walls are also investigated. Results from transmission and reflection measurements give good agreement with each other and with other related work in the literature.