A frequency synthesizer is one of the most critical building blocks in any wireless transceiver system. Its design is getting more and more challenging as the demand for low-voltage low-power high-frequency wireless systems continuously grows. As the supply voltage is decreased, many existing design techniques are no longer applicable. his book provides the reader with architectures and design techniques that enable CMOS frequency synthesizers to operate at low supply voltages, at high frequencies with good phase noise and with low power consumption. In addition to updating the reader on many of these techniques in depth, this book will also introduce useful guidelines and step-by-step procedures on behaviour simulations of frequency synthesizers. Finally, three successfully demonstrated CMOS synthesizer prototypes with detailed design consideration and description will be presented to illustrate potential applications of the architectures and design techniques described. The book is intended for engineers, managers and researchers who are working or interested in radio-frequency integrated-circuit design for wireless applications.