Research On Key Technologies In Electromagnetic Compatibility Testing And Treatment Of A Number

With the rapid development of electrical and electronic technology, electromagnetic compatibility (EMC) problems in electronic equipment are often generated and haven’t yet been solved. The research of improving electromagnetic compatibility performance and testing methods is been more and more concerned. The key technologies in EMC include electromagnetic interference (EMI) and electromagnetic Susceptibility (EMS). In EMI, radiated measuring devices provided by the EMC standards are mainly Open Area Test Site (OATS) and anechoic chambers, which are too expensive and difficult to afford by general corporate and laboratory; and the low-cost GTEM cell used in EMI measurement is not mature with low accuracy and complex implementations. In EMS, due to the complex ESD process, complicated protection methods and the lagging study in ESD of our country, the systematic and comprehensive study of electrostatic discharge (ESD) problem with the highest frequency and damage is very necessary.In this paper, a number of key technologies in EMC testing and treatment was researched, including two parts:The first part is the problem of radiated EMI measurement in EMC:(1) GTEM cell hardware structure design, related algorithms with open field and radiated EMI diagnosis mechanism were introduced, which is used for radiated EMI testing.(2) The radiated EMI testing method in GTEM cell based on the different radiation EMI models was proposed. Radiated noise was extracted by polynomial model of which the error was compensated based on variance analysis. Contrast with3m anechoic chamber standard test results, the applicability of each algorithm on different EMI noise model can be determined by calculating the error and precision.(3) Two EMI noise experiments, car navigation systems and HD visual aids, were analyzed respectively to verify the theoretical on the above.The second part is the study of ESD in EMS.(1) The formation mechanism, discharge characteristics, discharge models and ESD coupling methods were described. ESD interference mechanism and suppression strategies were analyzed innovatively from conductive ESD and radiated ESD, which improve the efficiency of the treatment of the ESD problem.(2) A belt scale with conductive ESD problems and a power concentrator with radioactive ESD problems were analyzed to test the effectiveness of the above theory.Theoretical analysis and experiment results show that, GTEM cell research can make it for common mode and differential mode radiation measurement and diagnosis, and determine the applicability of each algorithm and improve the measurement accuracy of the GTEM cell, which provide a theoretical basis for GTEM cell applied in radiated EMI noise measurements; on the other hand, the research and experiment results show the effectiveness of ESD suppression strategy based on conductive ESD and radiated ESD, which improve the efficiency of the treatment of the ESD problem.