A V-band wide locking range CMOS frequency divider

This paper presents a V-band wide locking range 0.18-mum CMOS frequency divider. The resonator-based injection-locked frequency dividers (ILFD) inherently suffer from narrow locking range. The combination of common-node injection and direct injection is proposed to improve the signal injection efficiency and locking range. Compared to the conventional direct injection technique, the proposed technique is capable of doubling the dividerpsilas locking range. Operated at 1.4 V, the frequency divider core consumes 2.8 mW of power. The measured free running frequency and output power of the divider are 28.17 GHz and -22.84 dBm, respectively. The locking range is 4.9 GHz around the input frequency of 56 GHz. With high operating frequency, wide locking range, and low power consumption, this work achieves the excellent figure-of-merit (FOM), which is much better than the frequency dividers implemented in the same generation CMOS process. The overall chip size is 0.77 times 0.49 mm².