Experimental Study of the Shielding Effectiveness Performance Degradation for a Shielding Material Used in Protective Storage Pouch

摘要

This paper presents measurements method as well as some measurement results of electromagnetic shielding effectiveness (SE) performed for an example of multilayer protective material incorporated in storage pouch, which was dedicated to protect bank cards, car keyless and radio key system against theft of personal belongings or data by contactless or radio hacker attacks. Measurements of EM shielding effectiveness were performed separately in frequency range from 1 MHz to 30 MHz using loop antennas for magnetic field and in frequency range from 10 MHz to 8.5 GHz adopting ASTM D4935-10 method for electric field. Measurements were conducted for a reference sample – a brand new multilayer material "used to fabricate a protective storage pouch as well as for two samples of the same material obtained from different protective storage pouches after their one year usage to protect contactless remote car keys and bank cards. Obtained results showed a significant degradation of the shielding effectiveness values of protective material after one year usage due mechanical, environmental and chemical factors, and finally a lower level of electromagnetic protection of the storage pouch.