Ultra Wideband (UWB) is a radio
technology that is gaining in popularity and currently working its way through the FCC
It is anticipated that UWB will be in a variety of ways including:
High speed, low power data transmission.
Object penetrating Radar. (limited FCC approval)
Instead of a sinusoid/wave based transmission like traditional radio UWB uses hundreds of short bursts per second and transmits across a huge frequency range at very low power (under 0.05 milliwatts, with each pulse lasting less than one nanosecond). Anyone without a perfectly tuned reciever would simply see a transmission as background noise.
From the Time Domain Corp website:
"Ultra Wideband systems transmit signals across a much wider frequency than conventional systems and are usually very difficult to detect. The amount of spectrum occupied by a UWB signal, i.e. the bandwidth of the UWB signal is at least 25% of the center frequency. Thus, a UWB signal centered at 2 GHz would have a minimum bandwidth of 500 MHz and the minimum bandwidth of a UWB signal centered at 4 GHz would be 1 GHz. The most common technique for generating a UWB signal is to transmit pulses with durations less than 1 nanosecond."