In this Chapter, a short range radar system based on ultra-wideband (UWB) technology is presented. The radar and its applications were reserved during a long time to national defence, air security or weather services domains. Since a few years, with the emergence of new technologies, the radar applications were developed and become known in many sectors of daily life. The arrival of a new technology called Ultra-Wideband (UWB) allows in particular the development of compact and low-cost radar with multiple fields of applications. UWB uses very short non-sinusoidal pulses that have widths less than 1.5 ns, so that the spectrum of the transmitted signals may spread over several Gigahertz. This radar offers a resolution in distance of about a few centimetres, for example 15 cm for a pulse width of 1ns, making this system very interesting in several short range applications. UWB radar has many applications in Medical, Building, Surveillance, Security and Monitoring applications [Dam2007] and will appear more and more in our daily life. For example, UWB radar systems for local monitoring allow creating dome radar surveillance around a sensitive object or subject. These compact systems contain a small UWB radar with a range of about 10 meters, a standard radio system for transmitting the alarm in case of intrusion and a GPS system for localisation function. These systems can be engaged in public safety functions in buildings, aircrafts or for artwork protection in a museum, but also as an alarm system around a house or near a swimming pool to avoid too frequent small children drowning. Thanks to their sensitivity the UWB radar can detect movement as slight as a heart beat or breathing rate. These systems is responsive enough to accurately depict a heart rate as compared to others existing systems. UWB radar could be used as ground penetrating radar (GPR). GPR systems can obtain very precise and detailed images sub-soil. UWB radar is moved along surface and sends electromagnetic pulses into the ground. The analysis of received echoes can produce a very specific profile of underground. The investigation depth varies, depending on the type of ground, from a few meters in asphalt or clay to more than a hundred meters in limestone or granite, or even several kilometres into the ice. Finally, UWB radar could be used for short range collision avoidance as mentioned in this paper. This collision avoidance system, 24 GHz UWB Short Range Radar (SRR), was developed principally by European car manufacturers. It is a combination of an UWB radar and a