Millimeter-wave (mm-wave) frequency synthesizers in complementary metal oxide-semiconductor (CMOS) suffer from poor phase noise (PN), limited tuning range (TR) and high-power consumption. They are the key subsystems that typically limit the performance of mm-wave transceivers. This chapter presents a new architecture for mm-wave frequency synthesis that improves its PN performance and power efficiency. Various different techniques are introduced and demonstrated in a 60-GHz fractional-N all-digital phase-locked loop (ADPLL).