A 7-12 GHz Multi-Modulus Frequency Divider

A 7-12 GHz divide-by-256/260/264/268 multi-modulus frequency divider chain is designed and implemented in 0.18-mu m CMOS technology. The frequency divider chain consists of a divide-by-4 divider, a divide-by-4/5 dual-modulus divider, a divide-by-16 counter, and digital control logic circuits. To speed up the operating frequency, a current mode logic (CML) divider without tail current source and a modified D-Flip-Flip (DFF) merged with NAND gate function are adopted. The multi-modulus frequency divider chain demonstrates high operating frequency of 7 GHz to 12 GHz while maintaining reasonable dc power consumption of 19.95 mW.