This application note is written for people who need to understand the configuration and testing of ultra-wideband (UWB) devices, and some of the issues surrounding their use. A broad range of topics is addressed in this paper, including practical test techniques. Further details on many of them may found in the references in Appendix B. The basic concepts behind UWB signals are not new, but the radios are becoming more sophisticated. The signals are split into three main groups, depending on the signal generation technique: baseband-pulsed, pulse- modulated RF, and orthogonal frequency division multiplexing (OFDM). Pulsed signals have been used in air and ground-penetrating RADAR systems of various forms for many years. Ultra-wideband OFDM involves adapting standard OFDM principles to meet the regulatory requirements of an underlay technology. RADAR and position location in the form of radio frequency identification (RFID) tags are good applications of UWB, but it is the application to short range, very high speed data transfer that has recently triggered increased interest, and is the main focus of this application note. Communications applications like streaming video can make use of the latest mixed signal IC technology to provide viably-priced consumer devices. Spectrum allocation is the key to new radio development. In 2002 the FCC in the United States allocated 3.1 to 10.6 GHz for use with unlicensed UWB signals as an underlay technology. It has stimulated many proposals to meet the specific requirements of the ruling. The IEEE 802.15.3a Working Group is one of the bodies looking to develop a standard that can be used generally by the industry for high-speed communication. Similar to Bluetooth™, the Multi-Band OFDM Alliance Special Interest Group has been established to promote an open OFDM standard. Other groups in Europe, Japan, and Asia are also showing interest, but do not currently have definite spectrum allocation rules with which to work.