Investigation of composite materials selection and joint layout design to enhance EMI shielding of electronic equipment

Mottahed, Behzad D.; Manoochehri, Souran

doi:10.1002/pen.11709

Cited by 10 publications

(5 citation statements)

References 16 publications

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“…The continuous growth of the computer and telecommunication market has stimulated an extensive study of the electromagnetic (EM) shielding materials in order to prevent harmful EM interferences (EMI) originated from the RF systems instrumentation. Along with the usage of traditional EM materials with high EMI shielding effectiveness (SE) 1 such as laminated composites, conductive polymers, fibres and flakes, conductive fabrics, and paints, this motivates the development of a new family of low‐weight, corrosion‐resistance, mechanically strong, low‐cost nanocarbon based shielding materials with high performance in microwave operating frequency bands. Carbon nanotubes (CNT) due to their particular mechanical, geometrical, electronic and electromagnetic properties are now extensively studied for various microwave applications (see Ref.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

Мазов

Кузнецов

Мосеенков

et al. 2009

Physica Status Solidi (b)

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A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) composite is shown to present high electromagnetic (EM) shielding. EM shielding effectiveness (SE) was investigated in the frequency range 26-37 GHz (Ka-band). It was found that SE of the given composites strongly depends on MWCNT content. The highest EM attenuation reaching À37 dB at 28 GHz was observed for polymer film comprising 10 wt.% of MWCNT. Data on SE correlates well with the electrical conductivity measured by four-probe technique and by broadband dielectric spectroscopy (20 Hz-1 MHz). Both microwave and low-frequency analysis demonstrate low percolation threshold (lower than 1 wt.%) for the produced MWCNT/PMMA composites. At the same time significant electromagnetic interference absorbance demonstrates the contribution of the absorbance mechanisms specific for carbon nanostructures different of the main conductance mechanism.

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Section: Introductionmentioning

confidence: 99%

Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

Мазов

Кузнецов

Мосеенков

et al. 2009

Physica Status Solidi (b)

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“…The polymer matrix can be reinforced by dispersed electrically conductive fillers, such as carbon materials (carbon fibers, carbon black, CNT, graphene) or metallic (stainless steel, copper, or aluminum) particles or fibers, creating traditional composite materials or more complex and futuristic structures with a wide range of properties, from antistatic to conductive. [ 3,6,7,12,16–27 ]…”

Section: Introductionmentioning

confidence: 99%

Effect of processing conditions on electromagnetic shielding and electrical resistivity of injection‐molded polybutylene terephthalate compounds

Martins

Barbosa²,

Silva³

et al. 2021

Polymer Engineering & Sci

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This research introduces an analysis of the anisotropic electrical resistivity (ER) and its relation to the electromagnetic shielding effectiveness (EMSE) for two injection‐molded carbon‐fiber‐reinforced polybutylene terephthalates (PBTs). The properties were measured for 2‐mm thick injection moldings considering the effect of melt temperature, injection velocity, and flow distance. The results for one compound showed an EMSE in the range of 30–40 dB, while EMSE for a compound with lower filler content is in the range of 45–75 dB. A combination of higher temperature and higher velocity leads to an increase of EMSE for both compounds in the range of 3%–8.5%. However, the increase in flow path reduced the EMSE for both compounds up to 10%. A novel experimental apparatus was used to measure the anisotropic ER in the three directions, that is, parallel, perpendicular, and transversal to flow. It is evident that injection molding induced high anisotropy for both compound specimens, and, depending on the processing conditions, produced similar longitudinal resistivity (0.2–4 Ω.cm) but higher transversal resistivity (8–22 Ω.cm). ER properties were compared with EMSE, evidencing an inverse relation as expected. Furthermore, it was found that the longitudinal resistivity is the main contributor to the specimens shielding.

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“…Despite a significant progress in the shielding materials, the miniaturization of electronic devices and a continuous growth of their number have resulted in electromagnetic interference (EMI) impact on the environment (electromagnetic smog) . A new generation of the lightweight materials for efficient EMI shielding over a wide range of frequency is expected to solve this problem.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic Interaction Between Spherical Aerogels of Multi‐Walled Carbon Nanotubes

Krasnikov

Dorofeev

Smirnova

et al. 2017

Physica Status Solidi (b)

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Lightweight materials for efficient electromagnetic interference shielding over a wide range of frequency are of great interest. Aerogels of multi-walled carbon nanotubes (MWCNTs) distributed in a dielectric matrix may interact effectively with electromagnetic radiation. Moreover, being arranged in specific patterns, they can also provide metamaterial characteristics (e.g., negative refractive index). In the present paper, we have studied the interaction between two spheres of the carbon nanotube aerogels in order to obtain a comprehensive basis for producing periodic 2D and 3D structures of such aerogel spheres in a dielectric matrix. We have extended the open resonator technique to the case of two units of MWCNT aerogels in order to reveal the interaction between them. The performance of the system depends on the orientation of the electric field to the axis of the aerogel cluster: MWCNT aerogel spheres (d ¼ 4.5 mm) interact considerably at the gap between spheres $0.2λ (11.6 GHz) for perpendicular orientation, while, in case of axial orientation, the interaction is negligible even at the distances close to the contact between aerogels ($0.02λ). Additionally, the cluster of two carbon nanotube aerogel spheres provides the polarizability close to that of copper spheres while having only 1% of their weight.

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Investigation of composite materials selection and joint layout design to enhance EMI shielding of electronic equipment

Cited by 10 publications

References 16 publications

Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

Effect of processing conditions on electromagnetic shielding and electrical resistivity of injection‐molded polybutylene terephthalate compounds

Electromagnetic Interaction Between Spherical Aerogels of Multi‐Walled Carbon Nanotubes

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