Small Die Area Capacitive Cross-Coupled Injection-Locked Frequency Divider

This letter presents a lower power and wide locking range divide-by-2 with capacitive cross-coupled injection-locked frequency divider (ILFD) implemented in the TSMC standard 0.18 mu m CMOS process. The ILFD is based on a capacitive cross-coupled VCO with one injection MOSFET for coupling the external signal to the resonator. The ILFD uses one 3-dimensional inductors to reduce the die area. At the supply voltage of 1V, the divider's free-running frequency is 2.27 GHz, and at the incident power of 0 dBm the locking range is about 5.9GHz (132.58 %) from 1.5GHz to 7.4 GHz. The core power consumption is 10.22mW. At low power mode, the ILFD has higher figure of merit. The die area is 0.719x0.637 mm(2).