In this paper, UWB communication system dispersive phenomena has been investigated, which are divided into three types: frequency, resonant, and multipath dispersion. Existing wideband channel models are extended by incorporating dispersion mechanisms that have not been previously considered. This paper presents a novel dispersive channel model that incorporates the frequency-dependent scatterer response based upon the singularity expansion method (SEM) for scatter characterization. The scatterer response is determined using the least-square Prony's method. Initial experimental results are also presented for a simple two-path channel