A 0.6V 2.2mW 58-to-73GHz divide-by-4 injection-locked frequency divider

A simple but effective locking range enhancement technique is proposed for LC-type divide-by-4 injection-locked frequency dividers (ILFDs) at millimeter-wave (mm-Wave) frequencies. By employing a 4th-order LC tank with the two frequency peaks properly designed at ω
₀
and 3ω
₀
, the 3
^rd
-order harmonic gets boosted that significantly enhances the injection efficiency and thus the locking range of divide-by-4 ILFDs. Implemented in 65-nm CMOS, the prototype measures a locking range of 21.9% from 58.53 to 72.92 GHz while consuming 2.2mW from a 0.6V-supply, which corresponds to an FoM of 6.54.