Phase noise formula for dual-resonance injection-locked frequency dividers

This letter develops a phase noise formula for injection-locked frequency dividers (ILFDs) implemented with dual-resonance LC tank, which consists of a series LC resonator and a parallel LC resonator. In parallel-tuned single-resonance ILFD, the output phase noise is set by the noise of the injection signal at low frequency offset from the carrier, while it can be dominated by the divider noise at large frequency offset. The developed theory shows that the phase noise equations of a series-tuned single-resonance ILFD and dual-resonance ILFDs has a common phase noise equation as the one used for a single-resonance parallel-tuned ILFD. (c) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2491-2494, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27105