Carbon NanoTube Field-Effect Transistors (CNTFETs), which utilize a single carbon nanotube or an array of carbon nanotubes as the channel material instead of bulk silicon in the traditional MOSFET structure, are now used in many microelectronic circuits for the realization of integrated nanosystems. This book, based on the most original research results carried out by the Authors in the last years, collects nine chapters, dedicated to the analysis and design of CNTFET based analog and digital circuits, with particular attention, for each circuit examined, to the effects of temperature and noise to define the optimal operating conditions.