Analysis and Design of 8-to-101.6-GHz Injection-Locked Frequency Divider by Five With Concurrent Dual-Path Multi-Injection Topology

Based on a detailed analysis of harmonic generation in ring-based injection-locked frequency dividers (ILFDs), this article shows that concurrent injection signals can be generated in these stages by driving both tail and direct injectors with the same input signal. Based on this result, a novel ring-based divide-by-five ILFD is presented, where multi-injection is reinforced by a dual-path scheme, largely broadening the locking range with no penalty in power dissipation. The stage, implemented in a 28-nm CMOS process, operates over the 8-to-101.6-GHz frequency range achieving a >20% locking over the 13.6–69.1-GHz interval, with 5.6-mW maximum power consumption from a 0.9-V supply. The stage also achieves 101.6 GHz, the highest operating frequency among state-of-the-art CMOS ILFDs by five, with 2.6% locking range.