This paper present a 60 GHz injection locked oscillator in 65-nm CMOS technology. The injection locked oscillator is a key component to realize an ultra-low power self-mixing architecture wake-up radio. In this paper, different methods of injecting a signal into the oscillator are discussed and the current re-use method is implemented to increase the sensitivity and improve the isolation while at the same time minimize the loading effect to the oscillator LC tank. The implemented oscillator provides 7 GHz locking range with 6 mW power consumption.