An ultra wide band (UWB) millimeter (mm) wave radar system includes a signal source having a control input, a GHz signal output and a frequency controlled output. A control loop is coupled between the GHz signal output and the control input including a frequency divider and a digitally controlled PLL that provides a locked output coupled to the control input of the signal source to provide frequency locked output signals that are discrete frequency swept or hopped. A frequency multiplier is coupled to the frequency controlled output of the signal source for outputting a plurality of mm-wave frequencies. An antenna transmits the mm-wave frequencies to a surface to be interrogated and receives reflected mm-wave signals therefrom. A mixer mixes the reflected mm-wave signals and mm-wave frequencies and processing circuitry determines at least one parameter relating to the surface from the mixing output.