an ultra wide band millimeter 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 .