A wide-locking range divide-by-2 LC-tank injection-locked frequency divider

A new wide locking range injection-locked frequency divider (ILFD) using a standard 0.18 µm CMOS process is presented. The ILFD is based on a differential VCO with one injection MOSFET for coupling the external signal to the resonator. The locking range of the ILFD is increased by using a new LC resonator. Measurement results show that at the supply voltage of 0.75 V, the divider's free-running frequency is tunable from 3.91 to 3.956 GHz, and at the incident power of 0 dBm the locking range is about 7.07 GHz (91 %), from the incident frequency 4.23 to 11.3 GHz. The ILFD has a record locking range percentage among published divide-by-2 LC-tank cross-coupled ILFDs.