Improvement of Electromagnetic Shielding Effectiveness for Radar Frequencies (X-Band) Using Dispersion Factor



Zaroushani V¹ ; Khavanin A¹ ; Mortazavi SB¹ ; Jnonidi A² Show Affiliations
Source: Iran Occupational Health Published:2016

Abstract

Background and aims: X-band with 8-12.5 frequencies range has various applications such as air control traffic, navy communication etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Currently, application of the shielding is a superior control for prevention of microwave exposure. This study investigated the effect of dispersion on shielding effectiveness improvement about a novel nanocomposit shiled. Methods: Nanocomposites prepared by epoxy resin and nano nickel oxide (7wt%) with 2, 4 and 6 mm thicknesses. In order to investigate the effect of dispersion, 10 and 66 minutes was considered as mixing time. Nanoparticles characterized by X-ray Diffraction and Field Emission Scanning Electron Microscope. Shielding effectiveness measured with vector network analyzer. Results: Dispersion of nanoparticles in group 2-nanocomposites was better than group 1-nanocomposites. Average of percentage attenuation in group 2-nanocomposites was better than group 1- nanocomposites. The Average of shielding effectiveness for three thicknesses in group 1 was 46.5, 69.03, 70.83 and for group 2 was 52.02%, 78.48% and 84.14%dB, respectively. Maximum attenuation obtained by the 6mm thickness in group 2- nanocomposites at 8.8 GHz frequency (91.12%). The Average of shielding effectiveness increased with increasing the thickness. Conclusion: With increasing the mixing time, the dispersion and shielding effectiveness be improved. These nanocomposites could be used as appropriate shielding for exposure control of X-band frequency in workplace and nanocomposite with 4mm thickness is appropriate shield in this study. Both 4mm and 6mm thicknesses in group 2 are useful in specific frequency such as 8.8 and 12.5 GHz.the average of percentage attenuation for above thicknesses is more than 87%. © 2016; MA Healthcare Ltd. All rights reserved.