An Equivalent Modeling Method For The Electromagnetic Radiation Of PCB Based On Near-field Scanning

PCB is not only an important electrical part of information devices,but also one kind of electromagnetic radiation sources.Its good performance and compatibility with other electrical modules are the fundament guarantees for a product to operate normally.Because of the complexity of PCB structure,modeling becomes a huge challenge for electromagnetic compatibility(EMC)researchers.As a result,it makes great significance to establish a simple equivalent model for the analysis of EMC.In this thesis,equivalent dipole modeling method of PCB and the application of equivalent model are studied.Three main aspects in this dissertation are as follows.(1)Study on equivalent dipole modeling method of PCB.To solve the moment of equivalent dipole array,electromagnetic near-field radiation data of PCB is obtained by near-field scanning.Because of the singularity of electromagnetic inverse problems,Tikhonov optimization method is applied in the process of calculation.The whole equivalent dipole model of common micro-strip line model and partial equivalent dipole model of complex PCB are established,and their near-field scanning parameters and distribution parameters of equivalent model are also illustrated in detail.Lastly,the accuracy and feasibility of the equivalent model method are validated by simulation.(2)Study on board-level electromagnetic interference of PCB based on the equivalent dipole model.Firstly,establish a Huygens' s box as the hypothetical boundary between noise source and victim source,and respectively use equivalent dipole model of noise source and victim source to calculate the tangential electromagnetic field on the outside and inside surfaces of Huygens' s box.Then based on the reciprocity theory,the coupling parameter of electromagnetic interference is calculated.This method is verified by M micro-strip line add patch antenna model and patch antenna array.(3)Study on electromagnetic leakage of the PCB in an enclosure with small apertures based on the equivalent dipole model.Research on the traditional co-simulation method to predict the electromagnetic leakage.Then based on model-expansion method and diffraction theory of small hole,an analysis method to calculate the electromagnetic leakage of PCB from aperture cavity is proposed by using equivalent model.This method is validated by the M micro-strip line with aperture cavity.Finally,the availability of replacing original PCB by equivalent dipole model to predict the electromagnetic leakage is analyzed.