The EMC Analysis Of Microstrip Based On Finite Element Method

ABSTRACT:With the development of miniaturized and multifunctional electronic equipment, the Printed Circuit Board (PCB) is developing towards the trend of high-speed, high-frequency, high-density and high-integrity. While high-frequency aggravates the interference of components on PCB, leading that PCB would not work very well. Therefore, reducing electromagnetic interference and improving electromagnetic compatibility are the most important issue of PCB design.In this thesis the author has used High Frequency Structure Simulator (HFSS), simulation software based on Finite Element Method (FEM), to analyze the characteristics of single microstrip and couple microstrip. The results provide theory basis for optimum design of PCB.Firstly, some theories have been introduced briefly, including microstrip transmission, FEM, the mode of single line, reflection characteristics, crosstalk theory and the affection of the parameters. They provide theory basis for calculation and analysis.Secondly, reflection characteristics of the single microstrip have been analyzed. The right angle bend microstrip and S-type microstrip have been considered. Four parameters which affect the reflection characteristics are considered:cut size, width of bend, thickness of the dielectric material and permittivity of the dielectric material. Furthermore, Optimized design for microstrip could be presented, which could improve electromagnetic compatibility of PCB.Thirdly, crosstalk of couple microstrip has been analyzed. Four parameters which affect the crosstalk characteristic are considered:frequency, distance between microstrip, parallel length and thickness of the dielectric material. Based on the simulation results, the methods including reducing the parallel length, increasing the distance between microstrip and reducing the thickness, have been presented.