scholarly journals Design of a Lightweight Multilayered Composite for DC to 20 GHz Electromagnetic Shielding

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3144
Author(s):  
Paul Clérico ◽  
Lionel Pichon ◽  
Xavier Mininger ◽  
Olivier Dubrunfaut ◽  
Chadi Gannouni ◽  
...  

The work aims to design a trilayer composite dedicated to electromagnetic shielding over a large frequency range, from 1 Hz to 20 GHz. Analytical and numerical models are used to determine the shielding effectiveness (SE) of this composite in the case of a planar shield. The shield is constituted of a support layer, a magnetic layer, and a conductive layer. Two possible designs are considered. To simplify the numerical calculation, a homogenization method and the Artificial Material Single Layer (AMSL) method are used. The proposed composite shows a good shielding capacity over the whole studied frequency range, with shielding effectiveness higher than 17 dB and 75 dB, respectively, in the near-field (1 Hz–1 MHz) and far-field (1 MHz–20 GHz). Both homogenization and AMSL methods show good suitability in near-field and allow one to greatly reduce the calculation time.

2020 ◽  
Vol 71 (05) ◽  
pp. 432-437
Author(s):  
Ion Razvan Radulescu ◽  
Lilioara Surdu ◽  
Bogdana Mitu ◽  
Cristian Morari ◽  
Marian Costea ◽  
...  

Fabrics for electromagnetic shielding are especially relevant in nowadays context, contributing to human’s protection and wellbeing and to proper functioning of electronic equipment, in relation to electromagnetic compatibility. Fabrics with electromagnetic shielding properties employ two main technologies, namely insertion of conductive yarns and application of conductive coatings. Magnetron sputtering is a modern technology to enable conductive coatings with thickness in the range of nanometers onto fabrics. This paper aims to analyze contribution of various conductive textile structures out of both fabrics with inserted conductive yarns and coatings to Electromagnetic shielding effectiveness (EMSE). EMSE was measured in the frequency range of 0.1–1000 MHz by using a TEM cell according to standard ASTM ES-07. Results show a gain of 10–25 dB when introducing silver yarns in warp/ weft direction, a variation of 5–35 dB between conductive yarns out of silver and stainless steel and an up to 12 dB gain out of thin copper coating by magnetron plasma onto the fabrics with inserted conductive yarns


2018 ◽  
Vol 49 (4) ◽  
pp. 484-502 ◽  
Author(s):  
Dharmendra Nath Pandey ◽  
Arindam Basu ◽  
Pramod Kumar ◽  
Himangshu B Baskey

This study involves a comprehensive evaluation of electromagnetic shielding characteristics of multilayer three-dimensional conductive fabrics by using cotton/copper wrapped hybrid yarn in X band frequency range. Five, three-dimensional fabrics with different structural configuration, such as orthogonal, angle interlock, cellular spacer, multi-tubular spacer, and contour were produced. Three different series of all five structures was also developed using pure cotton fabric, conductive hybrid yarn in weft and one-third hybrid yarn and two-third cotton yarn in warp Also, the effect of vertical and horizontal polarization of electromagnetic waves on electromagnetic shielding effectiveness was studied. The comparative analysis of reflectance transmittance and absorption behavior was also undertaken. The results indicate that pure cotton fabric (A series) does not have electromagnetic shielding capabilities. The difference between the electromagnetic shielding effectiveness values in vertical and horizontal planes of fabrics, having conductive hybrid yarn in weft direction (B series), showed significantly better results on the vertical plane in comparison to that on the horizontal plane. Fabric containing conductive hybrid yarn in both warp and weft (C series) exhibits consistent electromagnetic shielding effectiveness in both the planes. It is worth mentioning that the structural configuration in all five three-dimensional fabrics in B and C series has shown differential trends of electromagnetic shielding effectiveness in terms of reflectance, transmittance and absorption behavior. They are also found to be statistically significant. Finally, it is concluded that the conductive 3-D multilayer system develops special protective capabilities, mostly due to its larger surface area.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
R. Rammal ◽  
M. Lalande ◽  
E. Martinod ◽  
N. Feix ◽  
M. Jouvet ◽  
...  

The aim of this work is to get far field radiation patterns for any radiating source from transient acquisition, in a large frequency range. An outdoor transient Ultra-Wideband near-field measurement base will be installed, a single time pulse radiated by the source will cover the desired spectrum, and the accurate determination of far field radiations will be accomplished by means of cylindrical waves' modal development. This method uses simplified test equipments, easy to be installed, and it reduces measurement costs.


2014 ◽  
Vol 910 ◽  
pp. 262-265
Author(s):  
Jia Horng Lin ◽  
Zhi Cai Yu ◽  
Jian Fei Zhang ◽  
Ching Wen Lou

In order to fabricate fabrics with electromagnetic shielding effectiveness (EMSE) and other function, we fabricated Crisscross-section polyester /antibacterial nylon / stainless steel wires (CSP/AN/SSW) composite yarns with stainless wires as core yarn, antibacterial nylon and crisscross-section polyester as inner and out wrapped yarns, respectively. Knitted fabrics were fabricated with the metal composite yarns with wrap amount of 8 turns/cm on a circular knitted machine. Furthermore, the EMSE of the metal composite fabrics were evaluated by changing the lamination amounts and lamination angles. The results show that when the lamination amount was four, lamination angles were 0°/45°/90°/-45°, the EMSE of the fabrics reached to-10--20 dB in the frequency range of 300 KHz to 3 GHz.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940020 ◽  
Author(s):  
Ming Gong ◽  
Shou-Guang Sun ◽  
Lin Sun ◽  
Ai-Qin Tian ◽  
Qiang Li

Computer Simulation Technology EM and Computer Simulation Technology Microwave Studio electromagnetic simulation software were used to simulate the carbon fiber composite materials with a new type of wide frequency electromagnetic shielding coating. DC magnetic field, low-frequency electromagnetic fields, and mid-high frequency electromagnetic shielding effectiveness analysis model were established in order to study the influence of permeability, conductivity, coating thickness and other parameters in the typical frequency range research on the shielding effectiveness. The results show that the composite coating material with reasonable design can effectively enhance the electromagnetic shielding performance of carbon fiber composite materials in the DC [Formula: see text]18 GHz frequency range.


2011 ◽  
Vol 239-242 ◽  
pp. 1994-1997 ◽  
Author(s):  
Ching Wen Lou ◽  
Yi Chang Yang ◽  
Chin Mei Lin ◽  
Ching Wen Lin ◽  
Lin Chao Chen ◽  
...  

Stainless steel (SS) blended yarns with electromagnetic interference (EMI) were made into woven fabrics, after which the fabrics were evaluated with electromagnetic shielding effectiveness (EMSE). Parameters of laminated angle and the lamination number layers affected the fabrics’ EMSE differently. In addition, density of unidirectional SS yarns affected EMSE in frequency range of 200 to 500 MHz , so as the density of cross SS yarns on a frequency over 1000 MHz.


Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 740
Author(s):  
Yanfei Pan ◽  
Dingwen Yin ◽  
Xiaofang Yu ◽  
Nanyi Hao ◽  
Jintian Huang

The lightweight multilayer-structured electromagnetic interference shielding composite coatings with controllable electromagnetic gradient on wood surface were prepared via a simple multiple electroless copper–nickel (Cu–Ni) approach. The surface morphology, conductivity, hydrophobicity property and electromagnetic shielding effectiveness of the composite coatings were investigated. The surface roughness and conductivity of the composite coatings were enhanced with the increase in the number of depositions. The surface morphology demonstrated that the roughness was decreased with the process of multiple electroless. The coatings were compact and homogeneous as the deposition run was three. Here, the Sa (Sa illustrated Surface Roughness) value of coatings was 4.497 μm. The ideal conductivity of composite coatings can be obtained as the number of depositions was four. Electromagnetic shielding effectiveness reached average 90.69 dB in the frequency range from 300 kHz to 2.0 GHz. This study provides a new pathway for fabricating lightweight multilayer-structured electromagnetic interference shielding with controllable electromagnetic gradient and hydrophobic composite coatings-based wood.


2010 ◽  
Vol 168-170 ◽  
pp. 997-1000 ◽  
Author(s):  
Guo Xuan Xiong ◽  
Zhi Bin Zhang ◽  
Min Deng

The cement-based composite shielding materials was prepared using portland cement and nickel fiber. The effects of dispersive manner, contents of nickel fiber, thickness of specimens on shielding properties and conductivity were studied in a frequency range of 100 KHz~1.5 GHz. With the contents of nickel fiber by ultrasonic dispersed at 5 vol.% and specimen’s thickness of 10 mm, the conductivity is 2.58×10-3 S•cm-1 and maximum shielding effectiveness is 47.8 dB, average shielding effectiveness reaches about 45.9 dB for cement-based composites.


2016 ◽  
Vol 87 (16) ◽  
pp. 2039-2047 ◽  
Author(s):  
Jia-Horng Lin ◽  
Po-Wen Hwang ◽  
Chien-Teng Hsieh ◽  
Yi-Jun Pan ◽  
Yueh-Sheng Chen ◽  
...  

This study prepares and explores the properties of three types of woven fabrics that have electromagnetic shielding effectiveness (EMSE), far infrared (FIR) emissivity, or both (EMSE/FIR). The EMSE woven fabrics use stainless steel (SS) staple blended yarn and the FIR woven fabrics use FIR polyester filaments. The woven fabrics are made with various structures, densities, lamination layers, and warp/weft arrangements in order to yield the optimum EMSE and FIR emissivity. The experimental results show that an increase in SS content slightly increases the EMSE at the frequency range between 300 and 600 MHz, but does not significantly increase the EMSE at a high frequency of between 2000 and 2200 MHz. However, using SS staple blended yarn for both the warp and the weft significantly increases the EMSE by between −8 and −16 dB. The FIR emissivity increases as a result of an increasing amount of FIR polyester filament and reaches the optimum, 0.88.


2021 ◽  
pp. 004051752110623
Author(s):  
Zhe Liu ◽  
Sijia He ◽  
Haoyu Wang ◽  
Xiuchen Wang

Blended electromagnetic shielding (EMS) fabrics of cotton/stainless steel/polyester have been widely applied. The porous structure of the fabric is the guarantee of its good comfort performance, but it also hinders the improvement of shielding efficiency and the endowing of wave absorption performance. To solve the above problems, this paper proposes a mixed resistance field based on fabric pores by the construction of multi-layer MXenes. Ti3AlC2 is etched by hydrochloric acid and lithium fluoride to generate hydrofluoric acid in situ to prepare multi-layer Ti3C2T x. The finishing experiments are designed to finish the fabric around the pores with Ti3C2T x impregnation. The enhancement effect and mechanism of the mixed resistance field on the shielding effectiveness and wave absorbing properties of the fabric are analyzed. The result shows that the multi-layer Ti3C2T x for textile finishing is prepared quickly and effectively using the proposed method. The micro media of the Ti3C2T x in the dispersion are adsorbed on the surface of various fibers, most of which are cotton fibers. The shielding effectiveness of the finished EMS fabric is improved significantly in the frequency ranges of 6.57–14 GHz and 11.97–18 GHz. The wave absorbing performances in the frequency range of 11.97–18 GHz are excellent. It is proved that the effect of the mixed resistance field of the pores was satisfactory. This paper provides a new way for the application of Ti3C2T x in EMS fabric, solves the disadvantages caused by pores, and can provide a reference for the design and production of wave absorbing EMS fabric.


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