Evaluation of Near-Field Electromagnetic Shielding Effectiveness at Low Frequencies

Arellano, Yessica; Hunt, A.; Haas, Olivier

doi:10.1109/jsen.2018.2873909

Cited by 13 publications

(8 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Applications of MIT include biomedicine, industrial process tomography and non-destructive diagnoses [7,8]. The accuracy of such investigations can be improved when the external EM interference is excluded [9]. EM waves can be shielded by materials based on reflection, absorption, and internal multiple reflections [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the effectiveness of an electromagnetic shielding enclosure at low frequencies

Wungmool,

Osaklung,

Kijamnajsuk

et al. 2023

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

We construct an electromagnetic shielding enclosure with dimensions of 95 cm × 95 cm × 95 cm. It is made from aluminum and copper which are high electrical conductors and nonmagnetic materials, so the enclosure does not produce additional static magnetic field. The enclosure is composed of a cubic frame (25-mm aluminium rails) and 6 removable panels. Each panel consists of a copper mesh (wire diameter of 0.25 mm and 0.58 mm spacing) sandwiched in a double layered aluminium frame, two aluminium handles, and 4 aluminium hooks. The electromagnetic shielding effectiveness of the enclosure is evaluated using the standard method at low frequencies, 0.4–25 MHz. A function generator and a circular flat coil with a diameter of 5 cm are used to transmit sinusoidal electromagnetic waves directed to the enclosure. The electromagnetic waves transmitted into the enclosure are measured by a spectrum analyser and another similar circular flat coil. The measurements show that when the frequency is increased from 0.4–2.5 MHz, the shielding effectiveness slightly increases from 42.2–48.6 dB. For the frequency between 3–25 MHz, the shielding effectiveness remains at around 49.6 dB with a standard deviation of 0.6 dB. Such shielding enclosure is potentially improving the accuracy of many investigating techniques which use electromagnetic waves with low frequencies including nuclear quadrupole resonance and magnetic induction tomography.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of the effectiveness of an electromagnetic shielding enclosure at low frequencies

Wungmool,

Osaklung,

Kijamnajsuk

et al. 2023

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…For the first time, an antenna of this type was proposed by Oliner [36] and was called the "leaky-wave". A typical antenna of this type is a surface waveguide with a periodic system of irregularities [37,38]. The presence of irregularities leads to the transformation of the surface waves into radiating waves.…”

Section: Introductionmentioning

confidence: 99%

A Promising Ka Band Leaky-Wave Antenna Based on a Periodic Structure of Non-Identical Irregularities

Shaaban

Ali

Yasseen

et al. 2022

Preprint

View full text Add to dashboard Cite

This paper presents a new periodic grooved dielectric leaky-wave antenna (LWA) with non-identical irregularities for an extremely high-frequency (EHF) range capable of performing efficiently in the Ka band through a stable gain, a decrease in the level of the side lobes, and the achievement of a narrower main lobe beam. It consists of a dielectric waveguide antenna placed inside a channeled rectangular metallic waveguide to improve performance. A dielectric rod was used to overcome the losses related to the propagation of electromagnetic waves in metal conductors. A grooved dielectric of a 21-element linear array is used to propose a simple approach for the synthesis of such antennas based on a modified energy method and is fed by a standard waveguide. It was designed and simulated at 37.2 GHz for satellite, 5G antennas, and radar applications. The major novelty of this study is the ability to control the direction of the main lobe through non-identical irregularities in geometric parameters, such as the width, height, and distance between each element. Radiation techniques have been studied extensively using simulations. A performance antenna with radiation efficiency 99.35%, gain 22 dBi, width of radiation pattern 3.2 ◦ , and side lobe level (SLL) -18.3 dB has been achieved.

show abstract

“…Conductive metals are known to shield high-frequency electromagnetic fields [1,2] thanks to eddy currents. Magnetic metals are able to shield low-frequency electromagnetic fields [3][4][5] thanks to their capacity to channel magnetic flux. Multilayered shields or biphasic composite, combining both conductive and magnetic metals, give interesting results in different frequency ranges [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

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.

show abstract

Evaluation of Near-Field Electromagnetic Shielding Effectiveness at Low Frequencies

Abstract: This document is the author's post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version may remain and you are advised to consult the published version if you wish to cite from it.

Cited by 13 publications

References 21 publications

Evaluation of the effectiveness of an electromagnetic shielding enclosure at low frequencies

Evaluation of the effectiveness of an electromagnetic shielding enclosure at low frequencies

A Promising Ka Band Leaky-Wave Antenna Based on a Periodic Structure of Non-Identical Irregularities

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

Contact Info

Product

Resources

About