The promising high data rate wireless applications at millimeter wave frequencies in general and 60 GHz in particular have gained much attention in recent years. However, challenges related to circuit, layout and measurements during mm-wave CMOS IC design have to be overcome before they can become viable for mass market. 60-GHz CMOS Phase-Locked Loops focusing on phase-locked loops for 60 GHz wireless transceivers elaborates these challenges and proposes solutions for them. The system level design to circuit level implementation of the complete PLL, along with separate implementations of individual components such as voltage controlled oscillators, injection locked frequency dividers and their combinations, are included. Furthermore, to satisfy a number of transceiver topologies simultaneously, flexibility is introduced in the PLL architecture by using new dual-mode ILFDs and switchable VCOs, while reusing the low frequency components at the same time.