Design of wide tuning injection locked frequency divider and LC_VCO for multi-standards applications

A design of divide-by-2 injection-locked frequency divider (ILFD) and LC_VCO is presented in this work. The ILFD circuit is realized with a differential CMOS LC-tank oscillator with an injection MOS. The proposed design accomplishes wide tuning range frequency by using binary weighted switched varactor in addition to a linearly varying varactor. It can be applied for multi-standard wireless applications. The tuning range of the ILFD carrier frequency is from 1.2 to 1.75GHz. At the injection signal power of 0 dBm, the locking range is about 1.1 GHz from the incident frequency 2.4 to 3.5 GHz. The phase noise of the locked output is −123.4 dBc/Hz at 1 MHz offset frequency. The power consumption of total circuit is 22.98mW. Only 6.19 mW is consumed by the ILFD.