Ultra wide bandwidth (UWB) signals are commonly defined as signals that have a large relative bandwidth (bandwidth divided by the carrier frequency) or a large absolute bandwidth .On the other hand, generating, receiving, and processing UWB signals poses significant challenges that require new research in signal generation, transmission, propagation, processing, and system engineering. In the past 20 years, UWB was used for applications such as radar, sensing, military communication and localization. A substantial change occurred in February 2002, when the Federal Communication Commission (FCC) issued a report allowing the commercial and unlicensed deployment of UWB with a given spectral mask for both indoor and outdoor applications in the USA. This wide frequency allocation initiated a lot of research activities from both industry and academia. In recent years, UWB technology has mostly focused on consumer electronics and wireless communications.