Phase Noise Modeling for Integrated PLLs in FMCW Radar

The effect of frequency modulation (FM) on the phase noise spectrum of a charge pump phase-locked loop (PLL) for frequency-modulated continuous-wave (FMCW) radar is investigated. The static phase error is calculated as a function of frequency ramp slope and basic PLL design parameters. The phase noise spectrum under FM is deduced from the spectrum in the steady state. Design guidelines for integrated PLLs to be used in FMCW radar are derived from theoretical considerations and experimental results from the literature.