During 2-year project “SAWtag” supported in frames of French program “Chaıre d'Excellence” a SAW tag and sensor system operating in the Ultra-Wide-Band (UWB) frequency range has been developed. Often SAW tags and sensors operate in 2.44 GHz ISM band using relatively narrow bandwidth B= 82.5 MHz. The characteristics of these devices can be improved using UWB technology. We have developed two prototype devices operating in 200MHz–400 MHz and 2000MHz–2500 MHz UWB frequency ranges. A UWB interrogating device (the “reader”) operating in continuous wave radar mode for 2.0–2.5 GHz range was developed and manufactured by T. Ostertag. The remote measurements show compressed RF pulses of about 2 ns duration, which include unique RF filling of a few sinusoids with amplitude modulation. Precise measurement of the pulse position is possible by correlation methods, avoiding the phase ambiguity problem. The temperature is measured with a precision of about 0.1 °C. This correlation method works even in an environment with strong reflections from metal objects. The short compressed pulses allow measuring a number of sensors simultaneously. For tag application, we measure and identify three different tags at the same time without a collision problem, and this number can easily be greatly increased. Using of Hyperbolically Frequency Modulated (HFM) signals in SAW-tags is also discussed. A UWB SAW-tag with extremely small chip size (0.8mm × 2.1 mm) has been demonstrated. We also briefly discuss the development of 6GHz SAW-tags.