Integrated frequency modulated continuous wave (FMCW) radar on chip (RoC) shows huge potential on real-time, versatile, wireless monitoring of human health conditions with low power, high sensitivity and compact size. This paper presents a Ku-band FMCW RoC working at 15 GHz center frequency, which can realize accurate continuous health monitoring based on interferometry phase analysis algorithm. A digital-tunable mixed-signal-mode FMCW chirp synthesizer is designed to ensure the phase accuracy with high power efficiency. A saturated driver-amplifier and power-amplifier chain is used to suppress the chirp ripples, thus ensuring the accurate phase measurement. Fabricated in 65 nm CMOS technology, the prototype demonstrates 1 GHz chirp bandwidth with 1.2 V supply and 238 mW power consumption, which satisfies the low-power requirement for continuous-time healthcare monitoring applications. Experiments on detecting various kinds of micro physiological signals are carried out using the FMCW radar chip prototype based on the phase analysis algorithm. The radar and the phase analysis algorithm can be further integrated into an ASIC to realize higher performance on healthcare monitoring.