Research On Modeling Of Electromagnetic Interference And Shielding For High Frequency And High Speed Electronic Devices

With the increasing integration of electronic devices,the working frequency bands of different devices may overlap and crosstalk occur,thereby affecting the normal operation of the entire system.Electromagnetic compatibility has become a problem that can not be neglected in the design process of electronic products.In order to reduce possible EMC problems and reduce the risk of rectification after the production and processing of the integrated circuit,we need to study the electromagnetic characteristics of the radiating devices in depth and propose effective equivalent models and analysis methods.Combined with engineering applications,this paper mainly focuses on high-frequency high-speed electronic devices in the electromagnetic interference and shielding aspects of modeling studies.Based on the research background and current situation,the main research of this paper includes the following aspects:1.The local components such as capacitors were modeled and error analysis of high-frequency parasitic parameters was performed.In this paper,genetic algorithm optimization circuit model parameters,the circuit model can accurately reflect the test case.From this we can create a database of component model parameters under the same process,which makes it possible to effectively predict components with different parameter values.2.An equivalent dipole model is constructed for the whole radiation module.By extracting the near-field radiation information of the device,an equivalent radiation source model based on the tangential magnetic dipole is established,and the accuracy of the equivalent source is verified by the simulation model and the actual device.This greatly increases the simulation efficiency and is suitable for analyzing the coupling of the module to the surrounding devices in the previous design.3.The near-field expression model of shield effectiveness is studied.Shielding structure is a common method to solve electromagnetic interference.For the shielding structure of radiation device,this paper presents a new form of near-field shielding effectiveness.Using the advantage of near-field scanning flexibility and convenience,we analyze the near-field magnetic field to represent the shielding effectiveness,and compare the near-field shielding effectiveness with the far-field shielding effectiveness measured by the reverberation room method.The consistency between the two verifies the rationality of the proposed field-shielding effectiveness formula,and thus provides a new and effective test method for measuring the shielding effectiveness of the small-size shielding structure.4.The problem of evaluating the far-field radiation of the equivalent model in a shielded box is studied.Shielding covers and shielding boxes are two common electromagnetic shielding applications.This paper analyzes the typical EMI sources in a complex electromagnetic environment and shielded enclosure EMI radiation scenarios.For the multi-scale simulation problem that the shield box is large and the circuit board is small,we construct the dipole equivalent model to replace the radiation source by the optimization algorithm and verify the accuracy of the far-field evaluation of the equivalent model in a shielded box environment.