During the last decade, ultra wideband (UWB) systems gained a large interest in the scientific world because of their suitability to realize among others communication systems with tremendous data rates and accurate indoor positioning and location systems. As a differing technology compared to classical narrowband radio transmission systems, UWB requires some novel approaches. Well established methods to develop and analyze narrowband transmission systems remain essentially valid but are not always well tailored or optimal to UWB systems. The need for novel approaches illuminates the reasons why there are still some uncovered topics in the literature, mainly related to the analyses of imperfections and perturbations during an UWB transmission. Consequently, this thesis attempts to cover some of these topics by theoretical studies, numerical simulations, as well as experimental verification.