A DDS and PLL-based X-band FMCW radar system

A DDS and PLL-based FMCW range meter system is described. The DDS is used as a reference clock of a linearly frequency modulated signal source, and the PLL is controlled by it. The bandwidth and the sweep time of the FMCW radar system are 150 MHz, and 270 us. Zero-padding and spectral centroid processing techniques are used to measure a target range, and the range resolution is less than 0.25 m.