框式设备网口辐射发射仿真研究

Research on Simulation of Radiation Emission for Network Interface of Framed Equipment

框式信息设备的网口辐射发射日益重要和复杂。文章以机框、网口变压器、印制电路板(PCB)及散热器等关键框式设备作为输入建立了完整的电磁模型,采用CST仿真分析了该模型在宽带内的辐射发射,并与实际测试值进行了比对,结果显示在工作频点仿真与测试一致。分析了辐射信号类型、PCB布局以及散热器接地与否对辐射发射能量的影响,并基于电磁辐射理论给出解释和布局指导。结果表明:共模信号较差模信号明显提高,在808 MHz辐射增强约20 dB以上;散热器接地明显降低辐射发射,比未接地时底部耦合场强降低15 dB以上;强辐射信号底部建议敷设地层以降低辐射。为产品风险快速评估及方案迭代优化提供了参考。

With the development of product iteration and technology,the radiation emission as the key of the electromagnetic compatibility test of the frame communication information equipment is becoming a real pain point.In this paper,the electromagnetic model of the internal device of the machine box,the printed circuit board(PCB)and the radiator,and the radiator in these key frames is established,and the radiation emission of the model in the band is analyzed by the CST simulation,and the results show that the simulation and test are consistent with the test.Based on this,this paper analyzes the influence of radiation signal type and radiator grounding on radiation emission energy,and gives explanation and layout guidance based on electromagnetic radiation theory.The results showed that the signal difference signal was improved significantly,and the radiation increased by more than 20 dB in 808 MHz.The radiator ground is significantly lower radiation emission,and it is less grounded in 808 MHz to lower the bottom coupling field and reduce the strength of the bottom of the coupling field by more than 15 dB.The strong radiation signal is recommended to lay the formation to reduce radiation.The article provides a reference for the rapid evaluation of product risk and the iteration optimization of the project.