A 0.35µm CMOS divide-by-3 LC injection-locked frequency divider

A divide-by-3 CMOS LC-tank injection locked frequency divider (ILFD) is proposed and implemented in a 0.35 mum CMOS process. The ILFD circuit is realized with a double cross-coupled complementary MOSFET LC-tank oscillator with two injection MOSFETs across the resonator inductors for signal injection. The self-oscillating VCO is injection-locked by third-harmonic input to obtain the division factor of three. Measurement results show that at the supply voltage of 2.0 V, the free-running frequency is from 3.18 GHz to 3.316 GHz. At the incident power of 0 dBm, the total locking range is from the incident frequency 9.41 GHz to 10.03 GHz. The power consumption of the ILFD core is 8 mW.