Analysis Of Electromagnetic Interference Path By Using The Transmission Line Equation On The Complex System

The increasing development of the electronic information technology, and the complex and diverse of electronic system internal structure result that the influence of electromagnetic interference on equipment during the operation is becoming more and more serious. Also, it is more difficult to calculate the interaction between the equipments. For solving the electromagnetic interference coupling problem, a modeling method based on electromagnetic topology theory is presented. We use the BLT equation in the transmission lines theory to calculate the model. Based on finding the shortest EMI path, the research on the intelligent algorithm is carried out.Firstly, makes a brief introduction of electromagnetic topology theory, and use the concept of pipeline and nodes in the theory to build topology model of the complex system. In a computer case as an example, introduce how to construct the electronic equipment electromagnetic interference topology.Secondly, in order to solve the electromagnetic interference problem of the complex system, make a simple derivation of the BLT equation. And then introduce the construction method of cable network of BLT equation and the calculation method of the related parameters in the equation First of all, with a simple ring structure as an example, list the network BLT equation and the parameters calculation results, then use the Matlab programming to obtain the voltage frequency response curve of each node. Next to a ring, tree, star, net form mixed structure of multiple conductor transmission line network as an example, through the detailed analysis of the network, use the BLT equation to calculate interference response in the transmission line network.Thirdly, introduce the main content of the genetic algorithm, and summarize the advantages and disadvantages of genetic algorithm. Based on the shortcomings of algorithm, propose the improvement that combines genetic algorithm and ant colony algorithm. Through the logarithmic transformation of S parameters, we can calculate the weights on the edge of the electromagnetic topology graph-shielding coefficient, then use the improved genetic algorithm to determine the shortest EMI path. And then through shielding the path effectively, achieve the purpose of reducing the electromagnetic damage, and improve the EMC performance.