Dataset Information

Quantitative Interpretation of Electromagnetic Interference Shielding Efficiency: Is It Really a Wave Absorber or a Reflector?

ABSTRACT: As electromagnetic (EM) pollution continues to increase, electromagnetic interference (EMI) shielding materials have been intensively evaluated in terms of two main shielding mechanisms of reflection and absorption. Since the shielding effectiveness (SE) is represented in the logarithmic scale and in a coupled way of transmission (SE_T), absorption (SE_A), and reflection (SE_R), often there is a misinterpretation that the EM wave reflectors are regarded as EM wave-absorbing materials. Surprisingly, we found that many materials reported as an EM wave absorber in the literature provide, in fact, less than 50% of EM wave-absorbing capability, i.e., over 50% of EM wave-reflecting feature. According to the theory and definition of EMI SE, the absorption-dominant EMI shielding materials should have the ratio of absorption to incident energy (A) as A > 0.5, which corresponds to a necessary condition that SE_R < 3.01 dB. The SE_R subsequently gives SE_A in relation to SE_T. Using this criterion, we classified the EMI shielding materials with their shielding mechanism. The proposed methodology provides significant insight into the evaluation and development of EMI shielding materials.

SUBMITTER: Hwang U

PROVIDER: S-EPMC8829945 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Quantitative Interpretation of Electromagnetic Interference Shielding Efficiency: Is It Really a Wave Absorber or a Reflector?

Hwang Uiseok U Kim Junyoung J Seol Mina M Lee Bumhee B Park In-Kyung IK Suhr Jonghwan J Nam Jae-Do JD

ACS omega 20220125 5

As electromagnetic (EM) pollution continues to increase, electromagnetic interference (EMI) shielding materials have been intensively evaluated in terms of two main shielding mechanisms of reflection and absorption. Since the shielding effectiveness (SE) is represented in the logarithmic scale and in a coupled way of transmission (SET), absorption (SEA), and reflection (SER), often there is a misinterpretation that the EM wave reflectors are regarded as EM wave-a ...[more]

PMID: 35155907

Similar Datasets

Project description:In this study, a self-healing hydrogel was prepared that is transparent to visible (Vis) light while absorbing ultraviolet (UV), infrared (IR), and microwave. The optothermal features of the hydrogel were explored by monitoring temperature using an IR thermometer under an IR source. The hydrogel was synthesized using sodium tetraborate decahydrate (borax) and polyvinyl alcohol (PVA) as raw materials based on a facile thermal route. More significantly, graphene oxide (GO) and graphite-like carbon nitride (g-C3N4) nanostructures as well as carbon microsphere (CMS) were applied as guests to more dissect their influence on the microwave and optical characteristics. The morphology of the fillers was evaluated using field emission scanning electron microscopy (FE-SEM). Fourier transform infrared (FTIR) attested that the chemical functional groups of the hydrogel have been formed and the result of diffuse reflection spectroscopy (DRS) confirmed that the hydrogel absorbs UV while is transparent in Vis light. The achieved result implied that the hydrogel acts as an essential IR absorber due to its functional groups desirable for energy efficiency and harvesting. Interestingly, the achieved results have testified that the self-healing hydrogels had the proper self-healing efficiency and self-healing time. Eventually, microwave absorbing properties and shielding efficiency of the hydrogel, hydrogel/GO, g-C3N4, or CMS were investigated, demonstrating the salient microwave characteristics, originated from the established ionic conductive networks and dipole polarizations. The efficient bandwidth of the hydrogel was as wide as 3.5 GHz with a thickness of 0.65 mm meanwhile its maximum reflection loss was 75.10 dB at 14.50 GHz with 4.55 mm in thickness. Particularly, the hydrogel illustrated total shielding efficiency (SET) > 10 dB from 1.19 to 18 and > 20 dB from 4.37 to 18 GHz with 10.00 mm in thickness. The results open new windows toward improving the shielding and energy efficiency using practical ways.

Dataset Information

Quantitative Interpretation of Electromagnetic Interference Shielding Efficiency: Is It Really a Wave Absorber or a Reflector?

Publications

Quantitative Interpretation of Electromagnetic Interference Shielding Efficiency: Is It Really a Wave Absorber or a Reflector?

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets