A LC-Tank Injection Locked Frequency Divider with Complementary Structure

This paper presents a LC-tank injection locked frequency divider with Complementary structure. The frequency divider is implemented using a standard UMC 0.18-mum CMOS process. The proposed circuit adds an injection nMOS transistor between the differential outputs of the frequency divider with the structure of complementary VCO that contains a tapped LC resonator. The measurement results show that at the supply voltage of 1.2V. the divider free-running frequency is tunable from 1.86-GHz to 2.31-GHz, the locking range in divide-by-2 mode is about 1.52-GHz (35.7%), and the locking range in the divide-by-4 mode is about 2.05-GHz (24.4%). The core power consumption is 4.08mW.