Book excerpt: Wideband radio technology is not a new concept in the field of RF technology. Decades of research in the area of wideband systems has lead us to new possibilities in the design of low-power, low complexity radios. Ultra-wideband is a direct offspring, which takes the initiative a step further by presenting novel wideband techniques for RF technology. The US FCC position on UWB for commercial usage changed after agreeing to adopt the First Report and Order on February 14, 2002. Unlicensing several gigahertz of frequency spectrum allowed companies to manufacture and market products incorporating UWB technology. At a certain moment, the potential benefits of UWB were outweighed, when existing wireless (narrowband) regulators perceived UWB as a disruptive influence. This, however, did not stop most countries from accommodating and recognizing the true nature of UWB. In brief, the authors have only scratched the surface when it comes to understanding the true potential of UWB technology. The development stage is in its infancy and will necessitate a substantial amount of research to meet industrial specifications. Short-range communications, low-power and low/moderate data rate throughput are the most attractive aspects and promises of UWB technology. For this very reason, applications, such as wireless sensor networks (WSN) are most noticeable.