Artificial Surfaces and Media for Electromagnetic Absorption and Interference Shielding

2021 ◽  
Author(s):  
Pai-Yen Chen ◽  
Mohamed Farhat ◽  
Zhilu Ye ◽  
Muhammad Amin ◽  
Hakan Bagci ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Recent Progress ◽  
Performance Comparison ◽  
Emi Shielding ◽  
Low Profile ◽  
Artificial Surfaces ◽  
Negative Impacts ◽  
And Performance ◽  
Electromagnetic Pollution

The rapid advent of radio-frequency (RF) and microwave technologies and systems have given rise to serious electromagnetic pollution, interference and jamming for high-precision detection devices, and even threats to human health. To mitigate these negative impacts, electromagnetic interference (EMI) shielding materials and structures have been widely deployed to isolate sophisticated instruments or human settlements from potential EMI sources growing every day. We discuss recent advances in lightweight, low-profile electromagnetic absorbing media, such as metamaterials, metasurfaces, and nanomaterial-based solutions, which may provide a relatively easy solution for EMI shielding and suppressing unwanted RF and microwave noises. We present a general review of the recent progress on theories, designs, modeling techniques, fabrication, and performance comparison for these emerging EMI and electromagnetic compatibility (EMC) media.

Interface design of carbon filler/polymer composites for electromagnetic interference shielding

2021 ◽  
Author(s):  
Runxiao Chen ◽  
Rongrong Yu ◽  
Xiaoyuan Pei ◽  
Wei Wang ◽  
Diansen Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Interface Design ◽  
Electrical Equipment ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Carbon Filler ◽  
Portable Electronics ◽  
Electromagnetic Pollution ◽  
Carbon Based

The extensive use of electrical equipment and portable electronics has aroused major concerns about electromagnetic pollution. Carbon-based polymer composites are widely used in the electromagnetic interference (EMI) shielding field, motivated...

Ultrathin graphene: electrical properties and highly efficient electromagnetic interference shielding

2015 ◽  
Vol 3 (26) ◽  
pp. 6589-6599 ◽  
Author(s):  
Mao-Sheng Cao ◽  
Xi-Xi Wang ◽  
Wen-Qiang Cao ◽  
Jie Yuan
Keyword(s):  
Electrical Properties ◽  
Information Security ◽  
Rapid Growth ◽  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Electronic Devices ◽  
Strong Absorption ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Electromagnetic Pollution

Ultrathin graphene, a 2D material, demonstrates outstanding features and rapid growth for EMI shielding due to its strong absorption towards electromagnetic waves in composites. It is sought after for communication, electronic devices, information security, electromagnetic pollution defense and healthcare.

Preparation and properties of graphene aerogel/cotton composite flexible fabric with electromagnetic interference (EMI) shielding function

2021 ◽  
pp. 152808372198927
Author(s):  
Peng Wang ◽  
Shuqiang Liu ◽  
Man Zhang ◽  
Gaihong Wu ◽  
Kaiwen Wang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Waterborne Polyurethane ◽  
Development Trend ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Graphene Aerogel ◽  
Emi Shielding Effectiveness ◽  
Aerogel Composite ◽  
Electromagnetic Pollution

In order to alleviate the problems caused by electromagnetic pollution and simultaneously adapt to the future development trend of flexible wearable electronic equipment, it is high time to focus on the research of light weight, flexible and efficient electromagnetic interference (EMI) shielding material. A graphene aerogel composite EMI shielding composite fabric was prepared by combining graphene aerogel with fabric through the connection of waterborne polyurethane. The influence of aerogel amount on the EMI shielding function of fabric was discussed, and the waterborne polyurethane dosage on fabric mechanics and fabric style was also investigated. The result shows the composite fabric EMI shielding effectiveness reached 28 dB when the graphene aerogel amount was 25 mL (only 0.066 mL/cm2), which has satisfied the civilian requirements (20 dB). A good adhesion fastness between graphene and cotton fabric was obtained and the mechanical strength was also improved when the content of waterborne polyurethane was 20 mL. Graphene aerogel electromagnetic shielding composite fabric with good electromagnetic shielding performance and less consumption of nano carbon materials will have a good industrial application prospect.

Effect of dielectric and magnetic nanofillers on electromagnetic interference shielding effectiveness of carbon/epoxy composites

2021 ◽  
pp. 002199832110526
Author(s):  
Hafiz Shehbaz Ahmad ◽  
Tanveer Hussain ◽  
Yasir Nawab ◽  
Shuaib Salamat
Keyword(s):  
Silicon Carbide ◽  
Zinc Oxide ◽  
Electromagnetic Interference ◽  
Electronic Devices ◽  
Skin Depth ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Frequency Range ◽  
Electromagnetic Pollution ◽  
Emi Se

Tremendous development in electronic devices and their indiscriminate use has created a severe problem of electromagnetic pollution. Different types of electromagnetic interference (EMI) shielding materials and structures are used to protect electronic devices from the harmful effect of electromagnetic pollution. A present study was conducted to compare the effect of dielectric and magnetic nanofillers on electromagnetic shielding effectiveness (EMI SE) of carbon fiber reinforced composite structures (CFRC). Composites structures were developed using different dielectric and magnetic nanofillers. Effect of nanofillers on microwave absorption properties and reduction in electromagnetic pollution was investigated. Relationship between electrical conductivity and EMI shielding effectiveness in L, S, C, and X-frequency range was also studied. Among the dielectric nanofillers, silicon carbide showed excellent EMI SE in X-frequency range, while among magnetic nanofillers, zinc oxide showed excellent EMI shielding characteristics in a broad frequency range of 100 MHz to 13.6 GHz. Among magnetic nanofillers, CFRC with zinc oxide nanofillers showed the lowest skin depth value of 3.32 × 10−4 mm and among dielectric nanofiller, CFRC with silicon carbide nanofillers gave the lowest skin depth value of 6.49 × 10−4 mm, implying their excellent potential in EMI shielding applications.

The Facile Preparation of Flexible Graphene/Carbon Nanotubes Hybrid Papers for Electromagnetic Interference Shielding

2019 ◽  
Vol 956 ◽  
pp. 87-98 ◽  
Author(s):  
Wei Liu ◽  
Kun Jia ◽  
Jiang Jiang Ma ◽  
Dong Hong Wang ◽  
Jian Yu Gu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Electronic Device ◽  
Impregnation Method ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Emi Shielding Effectiveness

A series of flexible graphene/carbon nanotubes (CNTs) hybrid papers were prepared by a facile impregnation method using cellulose papers as substrate. The impregnation cycles and sequence have a great impact on microstructure, electrical conductivity and electromagnetic interference (EMI) shielding performance of graphene/CNTs hybrid papers. The results showed that the surface of cellulose papers was covered by graphene and CNTs, forming continuous conductive networks. The graphene/CNTs hybrid papers achieved a thickness range of 174.7-253.2 μm and areal density range of 26-35.7 g/m2, which presented a larger advantage than traditional EMI shielding materials. The electrical conductivity was increased from 0.33 S/cm to 7.63 S/cm with the increase of impregnation cycles from 1 to 5. Furthermore, graphene/CNTs hybrid papers delivered a high EMI shielding effectiveness of 22-32 dB in the frequency of 30-1500MHz, which was superior to single graphene or CNTs papers. Moreover, the electrical conductivity and EMI shielding effectiveness of as-prepared graphene/CNTs hybrid papers presented little decline after even bending 100 times at an angle of 180° owing to their excellent flexibility. The graphene/CNTs hybrid papers possess a huge application potential in electromagnetic compatibility (EMC) of electronic device. Key words: graphene; carbon nanotubes; electromagnetic interference shielding; cellulose paper; dielectric polarization

scholarly journals Electromagnetic Interference Shielding Anisotropy of Unidirectional CFRP Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1907
Author(s):  
Jun Hong ◽  
Ping Xu
Keyword(s):  
Carbon Fiber ◽  
Electromagnetic Interference ◽  
Fiber Orientation ◽  
Free Space ◽  
Theoretical Formula ◽  
Emi Shielding ◽  
Cfrp Composites ◽  
Set Up ◽  
Electromagnetic Pollution ◽  
Space Measurement

Carbon fiber-reinforced polymer (CFRP) composites have excellent mechanical properties and electromagnetic interference (EMI) shielding performance. Recently, their EMI shielding performance has also attracted great attention in many industrial fields to resolve electromagnetic pollution. The present paper mainly investigated the EMI shielding anisotropy of CFRP materials using a specified set-up of free-space measurement. The electrical conductivity of unidirectional CFRP composites was identified to vary with the fiber orientation angles, and the formula was proposed to predict the results consistent with the experimental. The obvious EMI shielding anisotropy of unidirectional CFRP composites was clarified by free-space measurement. The theoretical formula can predict the EMI shielding value at different carbon fiber orientation angles, and the predicted results were highly consistent with the experimental results. A comparison of the free-space measurement and the coaxial transmission line method was also conducted, which indicated that special attention should be paid to the influence of the anisotropy of CFRP composites on the shielding results. With those results, the mechanism of EMI shielding anisotropy of CFRP composites is clarified, which will provide an effective design of EMI shielding products with a designable shielding direction and frequency.

Design and Performance Comparison of Planar and Linear Antenna Array Using ADS

2014 ◽  
Vol 3 (2) ◽  
pp. 22-26
Author(s):  
V. S. Prabhu ◽  
◽  
V. P. Surya Surendran ◽  
V. G. Veena ◽  
◽  
...  
Keyword(s):  
Antenna Array ◽  
Performance Comparison ◽  
Linear Antenna ◽  
Linear Antenna Array ◽  
And Performance

SIMULATION AND PERFORMANCE COMPARISON OF VARIABLE SPEED MULTI-PHASE PMSM MACHINES

2018 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
MOIN SIDDIQUI KHADIM ◽  
FATMA AMREEN ◽  
KHURSHEED SIDDIQUI MOHD ◽  
◽  
◽  
...  
Keyword(s):  
Performance Comparison ◽  
Variable Speed ◽  
And Performance ◽  
Multi Phase
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