A 0.35 µm CMOS LC-tank injection-locked frequency divider

Abstract

A divide-by-2 injection-locked frequency divider (ILFD) has been designed in a 0.35 µm CMOS process. The ILFD circuit is realized with a differential CMOS LC-tank oscillator with an injection MOS. Simulation results show that at the supply voltage of 2.5 V and by tuning V tune from 0 to 2.5 V, the tuning range of the free-running ILFD is from 1.84 to 2.89 GHz. At the injection signal power of 0 dBm, the locking range of the proposed ILFD is about 2.49 GHz from the incident frequency 3.53 to 6.02 GHz. The ILFD dissipate 3.43 mW. At the tuning voltage of 1.6 V the simulated phase noise of the free running ILFD is −125.6 dBc/Hz at 1.066 MHz offset frequency at 2.65 GHz and the phase noise of the locked output is −132.7 dBc/Hz while the phase noise of the injected signal is −126.7 dBc/Hz.