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 0.35µm 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 0dBm, 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.