Current-Reused 6:1 Injection-Locked Frequency Divider

Abstract

This letter proposes a CMOS divide-by-6 injection-locked frequency divider (ILFD) with a divide-by-2 current-mode logic (CML) stacked on a capacitive cross-coupled oscillator used as an LC divide-by-3 ILFD. The divide-by-6 ILFD in the TSMC 0.18 μm 1P6M CMOS process has a measured locking range 1.7 GHz from 8.4 GHz to 10.1 GHz at the power consumption of 10.6 mW. The divide-by-6 ILFD uses the CML FD with wide locking range to track the input frequency from the LC sub-ILFD output, and occupies a die area of $1.2\times 1.2$ mm2. The LC sub-ILFD uses a dual-resonance resonator with two resonant frequencies, which can be used to extend the locking range.