Research On EMC Co-simulation Of PCB Circuit And Structure

In the traditional EMC Simulation field, structure designers and hardware designers in solving the problem of electromagnetic compatibility(EMC) design is usually independent of each other, and can not carry out effective collaborative design. Facing the increasingly strict situation on EMC requirement, this paper presents the method of EMC Co-simulation about printer circuit board(PCB) and equipment chassis, which can evaluate the electromagnetic compatibility of system more accurately.1. EMC characteristics of PCB circuit and structure have been discussed and summarized. In order to evaluate the electromagnetic compatibility of PCB in theory, the characteristics of PCB should be analyzed. Firstly, the characteristics of passive device in high frequency is introduced, then, two typical cases that cause the EMC problems, impedance discontinuity and return path of signal, is analyzed through calculation and simulation. Finally, we get the conclusion that the seams and slots of equipment chassis are the main factors that affect the electromagnetic leakage.2. EMC simulation of PCB circuit have been analyzed. The EMC problems of PCB can be subdivided into two parts: signal integrity and power integrity, which close to electromagnetic compatibility. In contrast to PCB level simulation softwares, EMC simulation process of PCB was put forward. The power integrity of PCB, mainly power/ground resonant impedance, was analyzed and related simulation was verified.The signal integrity problems on the PCB, mainly the crosstalk between signal networks,was simulatied. In order to evaluate the electromagnetic radiation performance of the whole board, finally the simulation results of near and far radiation field on the PCB was calculated.3. EMC Co-simulation of PCB circuit with equipment structure have been studied. For the simulation of electromagnetic radiation of electronic equipment case, the traditional method is using equivalent antenna to replace the real PCB. This method cannot reflect the real situation of space electromagnetic radiation. This paper puts forward the method of dynamic link between different simulation softwares, using results of thePCB’s near field radiation, loading on the structure simulation software model of PCB, whick can reflect the real electromagnetic radiation in equipment case more accurately. Using this method, the electromagnetic radiation of equipment case consists of single PCB and PCB groups was simulated. Combined with the theory of transfer impedance, the shielding effectiveness of equipment case with conductive gaskets was calculated. The feasibility of the proposed co-simulation method was verified through above two examples.