A divide-by-3 injection locked frequency divider with single-ended input

This letter proposes a new divide-by-3 CMOS injection locked frequency divider (ILFD) fabricated in a 0.18-mu m CMOS process and describes the operation principle of the ILFD. The ILFD circuit is realized with a double cross-coupled CMOS LC-tank oscillator with an injection MOS. The self-oscillating voltage controlled oscillator is injection-locked by third-harmonic input to obtain the division order of three. Measurement results show that at the supply voltage of 1.8 V, the free-running frequency is from 1.62 to 1.89 GHz. At the incident power of 5 dBm, the locking range is from the incident frequency 4.85 to 5.7 GHz.