Research And Design Of 2.4GHz Dual-Loop PLL Frequency Synthesizers

PLL (Phase-Locked Loop) Based frequency synthesis is a basic technology in the wireless communication system. As a local oscillator module, a frequency synthesizer generates exact oscillation signal, and that does a decisive effect on the performance of the receivers.In this artical, the research and design of a PLL based frequency synthesizer whitch is working in the 2.4GHz band is completed. First of all, a simply introduction about the background knowledge of PLL frequency synthesize and its main application are described. Then, this artical outlines the history and development of PLL frequency synthesizers, a simple introduction for current research is also presented.Second, the basic structure of PLL system is introduced, and the mathematical model and the effect of each module in the system are discussed. Depending on this basis, it introduces phase-locked loop based frequency synthesizer. And a brief description of classification based on divide ratio is explained. It introduces the basic concepts of phase noise also.PLL frequency synthesizer modules are discussed, namely the phase frequency detector, charge pump, voltage controlled oscillator and divider. This article gives the modules used in the loop performance advantages, with emphasis on the use of dual-loop filter structure which is mentioned in the the article title.Finally, this article uses tsmc0.18um mixed-signal radio frequency technology to design circuit, and takes a single 1.8V voltage source. It finishes the simulation and verification with Cadence IC5141 development platform. Which VCO module goes through pss+pnoise and transient analysis, and gives its noise performance datum. PFD is given with logic simulation result, the CP is given DC characteristics. At last, it presents the frequency synthesis simulation results of the entire system.