A highly linear frequency ramp generator based on a fractional divider phase-locked-loop

A highly linear analog frequency ramp generator based on a fractional divider concept is presented. The frequency ramp linearity achievable in this fractional phase-locked-loop configuration is better than 10/sup -4/. This value is revealed by numerical simulations as well as by measurements performed. With a prototype synthesizer implemented in a FMCW-radar system suitable for distance and velocity measurements.