This paper presents an Ultra-WideBand (UWB) RADAR system for distance and breathing measurement based on a Step Recovey Diode emitter delivering 230 ps pulse signal width. The reflected signal by the target is sampled on an oscilloscope and the system shows a 1.3 cm human chest displacement when the target is 30 cm distant from the RADAR. Then, the oscilloscope is replaced by a low cost and low complexity CMOS circuit, developed in our laboratory and named Time Delayed Sampling and Correlation (TDSC). Experimental results show a resolution of 5 cm and a maximum range of 25 cm for a metallic target