ABSTRACT
The revolution in the space of consumer electronics has spurred research for electronically controlled digital tuning systems used to generate accurate and stable frequencies. This search has led the evolution of frequency synthesis methods from a manual tuning system to that of the modern sophisticated phase-locked loop (PLL) techniques. The use of PLL-based frequency synthesis has its roots in the evolution of coherent communication system. The chapter provides developing intuitive understanding of the fundamentals employed in the design of PLL-based synthesizer. It discusses integer-N PLL system, architecture, specifications, and circuits. The chapter outlines the system-level specifications to determine the complexity of the PLL system to be designed. It also discusses the issue of linear modeling of PLL in both continuous time and discrete time domain. The chapter describes the myriad architectural choices that can be made for different classes of radio frequency applications.
