A 19–48.3-GHz 6th-Order Transformer-Based Injection-Locked Frequency Divider With 87.1% Locking Range in 40-nm CMOS

This brief presents a 19–48.3-GHz fully-on-chip divided-by-2 injection-locked frequency divider (ILFD) based on a 6th-order transformer for a wide locking range in 40-nm CMOS technology. The proposed 6th-order transformer extends the resonator’s locking range by introducing more zeros and poles that could widen the frequency range satisfying the locking conditions. Furthermore, an inductive gain peaking technique is adopted to ensure start-up conditions and achieve low power consumption. The measurement results demonstrate a locking range of 29.3 GHz from 19 GHz to 48.3 GHz, which satisfies most applications for different nations’ 5G standards. The chip occupies a core area of 0.0518 mm2 and dissipates 2.88 mW from a 0.6-V voltage supply.