A novel wide locking range divide-by-4 injection-locked frequency divider (ILFD) is proposed in this paper and was implemented in the TSMC 0.18 mu m 1P6 M CMOS process. The divide-by-4 ILFD uses a cross-coupled voltage-controlled oscillator with a parallel-tuned LC resonator and two mixers in series to serve as an injection device. At the drain-source bias of 0.8 V and at the incident power of 0 dBm, the locking range of the divide-by-4 is 1.7 GHz, from the incident frequency 10.3-12.0 GHz, and the percentage of locking range is 15.25 %. The core power consumption is 11.98 mW. At drain-source voltage of 0.9 V, the locking range of the divide-by-4 is 2 GHz, from the incident frequency 10.1-12.1 GHz, and the percentage is 18.0 %. At drain-source voltage of 1.0 V, the locking range is 2.2 GHz (20.0 %) from 9.9 to 12.1 GHz. The die area is 0.492 x 0.819 mm(2).