Analysis Of Electromagnetic Shielding Effectiveness Of Chassis And PCB System

Due to the variety of electronic products,the number increased significantly,electronic circuits are increasingly complex.Electrical and electronic components and equipment gradually applied to people working and living in every corner,while bringing human convenience,they also produced a large number of electromagnetic interference,so that the human electromagnetic environment more and more severe.In order to avoid the influence of electromagnetic interference,usually can use electromagnetic shielding and other methods to reduce the equipment on other equipment or human adverse effects.Based on the theory of electromagnetic compatibility,this paper analyzes the efficiency of electromagnetic shielding between chassis and high-speed PCB by siwave and hfss of ANSYS.The main research is as follows:1.According to the definition of electromagnetic compatibility,the use of the chassis of the electromagnetic shielding technology,by changing the shape of the chassis slot,the number of chassis slot,the shape of the chassis,chassis materials and other parameters of the design of the chassis,the equipment to reduce the impact of electromagnetic radiation,Can work properly.2.The resonant characteristics of 8-layer actual PCB are analyzed,In order to reduce the radiation of the equipment to the external equipment without affecting the performance of the equipment,we can choose to increase the decoupling capacitance at the position where the resonant frequency of the circuit board is strong,reduce the resonant frequency of the actual printed circuit board,Thus reducing the external electromagnetic radiation ability,and simulation of high-speed PCB board calculated near-field characteristics.3.In order to get closer to the actual situation,this paper,based on the study of the first and second steps,uses 8 layers of practical PCB board for electromagnetic shielding simulation.Because there may be multiple PCBs in the equipment,this paper will carry out collaborative simulation of electromagnetic compatibility of PCB boards,and study the impact of multiple PCB board at different locations on the chassis electromagnetic shielding,the design of the actual case has guiding significance.