A novel wide locking range divide-by-2 injection-locked frequency divider (ILFD) is proposed in the paper and was implemented in the TSMC 0.18-mu m 1P6M CMOS process. The divide-by-2 ILFD is based on a cross-coupled voltage-controlled oscillator (VCO) with an LC resonator and injection MOSFETs with source voltage coupled from ILFD output, and the injection MOSFET mixer is biased in subthreshold region. At the drain-source bias of 0.9 V, and at the incident power of 0 dBm the locking range of the divide-by-2 ILFD is 6.4 GHz; from the incident frequency 3.7 GHz to 10.1 GHz, the percentage is 92.75%. The core power consumption is 16.56mW. The die area is 0.839 x 0.566mm(2). Copyright (C) 2015 John Wiley & Sons, Ltd.