Research On The Test Method For Measuring The Shielding Effectiveness Of Electromagnetic Shielding Clothing

With the growing popularity of electronic products, the electromagnetic radiation field strength in the environment increases, endangering human health. In order to reduce or eliminate the electromagnetic radiation harm on human body, various electromagnetic shielding clothing emerged and has rapid developed. Although electromagnetic shielding clothing has been developed for many years, but there are not the shielding effectiveness measurement methods or internal and international standards of electromagnetic shielding clothing. Therefore, the corresponding measurement methods need to be urgently developed. This paper seeks to develop an effective method to test the electromagnetic shielding clothing.This paper introduces the theory of electromagnetic shielding, analyzes the factors which have impacts on the shielding effectiveness of the electromagnetic shielding clothing. According to electromagnetic shielding theory, there are lots of factors, which are not only the fabrics' reflection Loss and absorption loss, but also the frequency of electromagnetic radiation sources, distances between clothing and radiation source, the arrangement of electromagnetic shielding clothing and the gaps in the clothing, have impacts on the shielding effectiveness of the clothing.We analyzed the testing principles of the material shielding effectiveness, and then the present shielding test methods have analyzed and compared. Because of the current inadequacy of the test methods which is to replace clothing with fabric, a method to test the electromagnetic shielding clothing in the Anechoic Chamber has put forward. We also discussed the testing frequency range, testing layout, test procedure, test data of processing and set up the test system of measurement for shielding effectiveness of the electromagnetic shielding clothing.In the electromagnetic shielding clothing test, the internal space of clothing is narrow and the field strength is not symmetrical. The electric probe which is put into the narrow space will disturb the initial field strength, and it will cause measurement error. So the probe's size should be taken into account in the test. In this thesis the shielding clothing and the electric field probe are simulated using simulation software HFSS. Receiving Antenna Modeling and Simulation in the antenna simulation is rarely seen in before papers. This paper has tried in this aspect, which include the setting of excitation sources, the impedance matching and the antenna factor Simulation Solution. Moreover, the disturbances caused by different sizes probes which put into the model of shielding clothing are qualitative analyzed, and the measurement errors caused by the special size of probe are detailedly analyzed.