A low power CMOS divide-by-3 LC-tank injection locked frequency divider

This article presents a divide-by-3 CMOS injection locked frequency divider (ILFD) fabricated in a 0.18um CMOS process. The ILFD circuit is realized with a complementary Colpitts CMOS LC-tank oscillator with an injection MOS connected between the voltage controlled oscillator (VCO) output and ground. The self-oscillating VCO 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 2.63 to 3.29 GHz. At the incident power of -6.5 dBm, the locking range is from the incident frequency 8.84 to 9.90 GHz. At the supply voltage of 1.8 V, the core power consumption is 3.06 mW. The chip area is 0.972 x 0.574 mm(2). (C) 2007 Wiley Periodicals, Inc.