Research On The Algorithm Of Equivalent Radiation Source Reconstruction Based On Near-field Scanning Of Surface Electromagnetic Field

With the vigorous development of advanced chip manufacturing,electronic products tend to be miniaturized,highly integrated,mobile,high-frequency,and low power consumption.At the same time,the electromagnetic interference problem of electronic products is getting more and more serious.For traditional full-wave simulation methods:From the technical aspect,you need to know the specific internal structure of electronic products.For complex electronic products,it involves electromagnetic radiation coupling at multiple scales(PCB level,Component level,Chip level).The simulation is difficult,and requires a lot of computing resources and long calculation time;from the commercial aspect,many devices have intellectual property protection,and it is difficult to obtain their electromagnetic models.Due to the low cost of the near-field scanning method,combined with the equivalent radiation source algorithm,there is no need to know the internal structure of the measured object,and the ideal electromagnetic measurement effect can be achieved.In this dissertation,on the basis of near-field scanning technology,a high-efficiency equivalent radiation source reconstruction algorithm is studied.The main research of this dissertation is as follows:1)In the reconstruction algorithm with phase equivalent radiation source,this dissertation adopts an array of equivalent electromagnetic dipoles to equivalent physical radiation sources.This dissertation proposes a method for obtaining regularization parameters based on singular value decomposition.Under the premise that the reconstructed electromagnetic field has the same accuracy,this method is faster than the traditional L-curve method for obtaining regularization parameters.On this basis,taking the U-shaped microstrip line simulation model as an example,the influence of different electromagnetic field component input combinations on the reconstruction of the equivalent radiation source is studied in the case of load short circuit,load open circuit and load matching.This dissertation has the following conclusions:there are components with a small proportion of the phase radiation source,corresponding to poor reconstruction accuracy;the more input components,the better the overall reconstruction accuracy;the reconstructed components are the type of input components,and the accuracy is better than none The effect of reconstruction of the input components is better.2)In the reconstruction algorithm with phaseless equivalent radiation source,in order to improve the efficiency of the algorithm for reconstructing the radiation source without phase electromagnetic field input,this dissertation uses the patch antenna simulation model as an example to study the traditional double-sided iterative method.In order to reduce the scanning workload,on the basis of the double-sided iterative method,this dissertation proposes a direct single-sided iterative method that only retains one scanning surface.In order to further reduce the calculation time of the single-sided iterative method,this dissertation proposes to split into two groups of single-sided iterative processes according to the nature of the components,and then the two groups of single-sided iterative data share the equivalent radiation source and alternate iteratively.Combining the simulation results and the experimental results of the commercial power divider,it is shown that under the premise that the input data volume is huge and the accuracy is not much different,the calculation time is from short to long,component-based cross iteration method,direct single-sided iteration method and Two-sided iteration method.Through the research in this dissertation,an efficient reconstruction algorithm for equivalent radiation sources with and without phase electromagnetic field input is obtained,which provides quantitative guidance for electromagnetic interference analysis of complex electronic products.