Injection-Locked quadrature voltage-controlled oscillator (QILO) is designed in this paper at 117GHz frequency. To get good low-phase performance, sub-harmonically injection locked structure is used. A 38.8 ∼ 39.3GHz input signal is sub-harmonically injected in parallel to the tank and core quadrature VCO is designed as a parallel-coupled scheme. The chip is fabricated in a 65nm CMOS technology and shows a phase noise -100.9dBc/Hz at 1MHz offset, a tuning range of 116.7 ∼ 117.7GHz, a locking range of 0.4GHz, a 50-ohm matched output power of -10 ∼ -11dBm, and a simulated phase error of 1.7°.