A CMOS direct injection-locked frequency divider with locking range enhancement

This paper proposes an X-band direct injection-locked frequency divider (DILFD) with locking range enhancement by using CMOS 0.18-µm process. The direct injection-locked scheme features wide locking range, low input capacitance, and high frequency capability. This circuit adopts series peaking technique and parallel both PMOS and NMOS in cross-coupled pair to increase the locking range and also decrease the power consumption. The DILFD features a locking range of 18.5–22.5 GHz, and the power consumption is 7.9 mW. Moreover, the overall chip size is 0.462 mm².