Signal Integrity Analysis And PCB Improvement Based On MG2470in High Speed ZigBee System

With the development of electronic technology and the progress of the IC (Integrated Circuit) design, Electronic equipment has been moving toward the direction of high frequency and large-scale integration, and high-speed electronic devices whose operating frequency exceeds100MHz are ubiquitous. High-speed circuit has brought development to the electronics industry, but at the same time it also causes some problems that can not be ignored. That is the integrity of the high-speed circuit, including power integrity, signal integrity and electromagnetic compatibility problems. These three factors determine whether high-speed circuit can operate properly and stably.At present, the main solution to these three major issues is high-speed circuit simulation. We can obtain optimum value of the components, as well as the most desirable PCB (Printed Circuit Board) layout and routing scheme through simulation, Then we make the PCB according to the simulation results to improve the design success rate and stability of the system.This paper firstly give a detailed discussion of power integrity and electromagnetic compatibility for high-speed circuits, and sum up the ways to address power integrity and EMC(Electro Magnetic Compatibility) problems.In the meantime, we get the model, simulation of reflection and crosstalk of signal integrity problems, and present the solution to reflection and crosstalk using Cadence emulation software. Finally, we use the ADS simulation software to get a high-speed ZigBee system schematic simulation and layout simulation, obtain the best value of the components as well as the most desirable PCB layout and routing program, and test the PCB. The testing results indicate that the design is quite good to meet requirements.Here are the main contents of the paper:(1).Using the Cadence simulation software to give a reflect simulation on the overload and underload, at the same time give a crosstalk simulation on different parallel length transmission lines, different spacing of the transmission lines and different line widths of the transmission line, accordingly drawn to improve the reflection and crosstalkand means.(2). Design a set of high-speed ZigBee system which have a transmission rate of 1Mbit/s, and give a simulation to RF section of the schematic using the ADS2009simulation software, obtained the best balun circuit and impedance matching circuit; at the same time, give a layout simulation to the RF part using ADS2009simulation software, obtained the best PCB layout and routing program.(3). Measured the produced PCB, obtained the reflection coefficient and transmission power of the system, the design is proofed to have achieved the design goal according to the measured result.