A wide locking range harmonic enhanced injection locked frequency divide-by-4 with low injected power level (Invited)

In this paper, a fully differential injection which enhances the harmonics in the injection locked frequency divide-by-4 is proposed to widen the locking range with low injected power levels. Designed in Global Foundries 65nm CMOS process, the proposed injection locked frequency divide-by-4 operating at 60 GHz, achieves a locking range of 20% from 54 GHz to 66 GHz with a low injected power of -5 dBm. The proposed injection locked frequency divide-by-4 consumes 3.2 mW from a low DC supply of 0.5 V. The core area of the proposed frequency divide-by-4 is 250 μm × 230 μm.