GSM900/1800 Two Band Mobile Phone RF Circuit Design

Global digital mobile system is an improving and successful technique, and has become world-range criterion. Many Chinese companies are concerned with the design of GSM mobile phone. This project is added at the background.The article reviews and analyses the design of RF circuit based on MOTOROLA GSM900M/1800M chipset. RF circuit design for GSM mobile phone concern on circuit design, transmission line, wireless communication standard, circuit debug, shielding, PCB design, and so on. So it is difficult relatively in mobile phone design. General speaking, more high the operating frequency, more difficult the circuit and PCB design. With the enhancing of operating frequency, the influence of distributing parameter of PCB and component increase, so the diversity between calculating value and practical value become obvious. RF design is also called "black art".This article stresses the design of PA control curve, synthesizer loop filter and balanced circuit match.The difficulty of this project is mainly on the design of PA control curve, synthesizer loop filter and RF PCB.Insuring the output TDMA signal meeting the time mask and transcient spectrum criterion defined by GSM standard is the key in the PA power control design. Before do it, theory analysis in time and frequency domain is necessary. So we have to measuring the PA control characteristic precise.PLL frequency synthesizer loop filter design relatives to phase lock knowledge. Making a synthesizer do well requires the engineer understanding the theory of phase lock loop. Compromising the system stability, phase noise, lock time reasonably is the key to this work. Method of extreme value phase margin is the effective way of estimating the stability in lock state.PCB design is another difficult and important work. It is in relation to transmission line, signal separating, shielding, and so on. The practice experience is very important in the PCB design.In design, to understand the operating method, it is necessary expound the mathematics analysis first, and then consider the specific method. Besides, we must consider the product cost, size and reliability.This article consists of 6 chapters. The chapter 1 summarizes the significance of the project. The chapter 2 to chapter 4 introduce the feature, development and theory of modern mobile communication, and contrast many method. The chapter 5 depicts the principle of chipset used in the project. The chapter 6 is the main portion of this article.