EURASIP Journal on Applied Signal Processing 2005:3, 252–272 c 2005 Hindawi Publishing Corporation Ultra-Wideband Radio Robert A. Scholtz Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA Email:
[email protected] David M. Pozar Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA 01003, USA Email:
[email protected] Won Namgoong Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA Email:
[email protected] Received 12 May 2004 The application of ultra-wideband (UWB) technology to low-cost short-range communications presents unique challenges to the communications engineer. The impact of the US FCC’s regulations and the characteristics of the low-power UWB propagation channels are explored, and their effects on UWB hardware design are illustrated. This tutorial introduction includes references to more detailed explorations of the subject. Keywords and phrases: UWB radio, UWB propagation, UWB antennas, UWB radio architectures, selective RAKE receivers, transmitted-reference receivers. 1. ORIGINS “BA[seband]R[adars] have been ... recently demon- strated for various applications, including auto It has been said that paradigm shifts in design and opera- precollision sensing, spaceship docking, airport sur- tion of systems are necessary to achieve orders-of-magnitude face traffic control, tanker ship docking, harbor col- changes in performance. It would seem that such events lision avoidance, etc. These sensing applications cover have occurred in the world of radio communications with ranges from 5 to 5000 ft .... the advent of ultra-wideband (UWB) radio. Indeed, several remarkable innovations have taken place in the brief his- Further applications resulted in the construction of a tory of UWB radio.