Prediction And Cancellation Method Of Electromagnetic Interference Based On Multiconductor Transmission Lines Theory

The prediction and cancellation method of electromagnetic interference(EMI)have become the focus of electromagnetic compatibility(EMC)research.The conventional prediction method requires a high test cost so that the new radiation sensitivity test method is required.However,in order to reduce the cost of post-rectification investment,the EMI problem caused by crosstalk has also been widely concerned.Thus,in this paper,a series of studies are carried out,which mainly include the following parts:Based on the multiconductor transmission line(MTL)theory,the model of EMI prediction and the model of field-to-wire coupling(FC)are established,respectively.Combined with the terminal boundary condition and the electromagnetic parameters obtained by the numerical method or ANSYS software,the EMI suffered by the port load is obtained.Finally,the simulation and experiment verify the validity of the established model and analyze the factors affecting EMI.However,the high cost problem of the radiated sensitivity test for the traditional FC,this is made possible by resorting to a generator circuit laid parallel and in proximity of the cable under test and fed at the terminations by two voltage sources,whose phase shift is suitably controlled.The proposed scheme is preliminarily investigated by simulation and subsequently verified by measurement,which is conducted by setting up the test platforms in anechoic chamber.Eventually,the results suggest that a new approach for radiated immunity test is availability.Meanswhile,in order to suppress the more serious EMI,it can be solved by two methods.Firstly,according to the loads values of terminations at each end,RC differential and RC inverting cancellation circuits are applied between the aggressor line and victim line,respectively.Secondly,the Singular Value Decomposition(SVD)of the relation of the terminal voltages with two-port,the cancellation circuits are used at input and output terminal of MTL respectively.The results of both softwave simulation and circuit experiment illustrate its correctness and effectiveness of the far-end crosstalk cancellaton.