Spotforming with an array of ultra-wideband radio transmitters

Ultra-wideband (UWB) array signal processing has the distinct advantage in that it is possible to illuminate or focus on "spots" at distant points in space, as opposed to just illuminating or steering at certain directions for narrowband array processing. The term "spotforming" is used to emphasize the property that point-focusing techniques with UWB waveforms can be viewed as a generalization of the well-known narrowband beamforming techniques. Because methods in spotforming can lead to powerful applications for UWB systems, in this paper we derive, simulate and experimentally verify UWB spot size as a function of frequency, bandwidth and array aperture.