Enhancement of image quality by using metamaterial inspired energy harvester

Alkurt, Fatih Özkan; Altıntaş, Olcay; Özaktürk, Melikşah; Karaaslan, Muharrem; Akgöl, Oğuzhan; Ünal, Emın; Sabah, Cumalı

doi:10.1016/j.physleta.2019.126041

Cited by 45 publications

(29 citation statements)

References 26 publications

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“…Some of the researchers are recently concentrating on the use of antenna in the fields of Industrial, Scientific and Medical (ISM) [25], planar array for Wi-fi applications [26,27] and cancer diagnosis [28]. Use of metamaterials for better performance of low profile antennas [29] and improving image quality [30] are explored by many. The electromagnetic properties of nano-metal-coated textile surfaces are investigated recently [31].…”

Section: Introductionmentioning

confidence: 99%

Double-Elliptical Shaped Miniaturized Micro Strip Patch Antenna for Ultra-Wide Band Applications

Jose¹,

Rekh²,

Jose³

2019

PIER C

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Greater design flexibility and newer miniaturization techniques are highly sought after by the commercial antenna industry and researchers. Micro-Strip Patch Antenna (MSPA) is finding huge applications in various fields of communication. In the present paper, the novel idea of Double-Elliptical Micro-strip Patch Antenna (DEMPA) is proposed for antenna miniaturization and higher design flexibility. Double-Elliptical Patch (DEP) is made as the combination of two half-elliptical patches having the same minor axis and different semi-major axes or the same major axis and different semi-minor axes. A DEP with different lengths of horizontally arranged semi-major axes and centrally given feed was considered here. The length of semi-major axis for right half-elliptical patch was varied while keeping the length of semi-major axis for left half-elliptical patch fixed. Design of DEMPA was carried out using Ansoft HFSS software, and the antenna has been fabricated and tested. The measured results were in good agreement with the simulated ones. The percentage reduction in effective patch area was found to be 8.33 for DEMPA compared to the corresponding elliptical patch antenna. The DEMPA covered the entire frequency range of Ultra Wide Band (UWB). With this novel shape, greater design flexibility along with miniaturization is achieved. The axial ratio analysis showed that the resulted antenna was of linear polarization.

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Section: Introductionmentioning

confidence: 99%

Double-Elliptical Shaped Miniaturized Micro Strip Patch Antenna for Ultra-Wide Band Applications

Jose¹,

Rekh²,

Jose³

2019

PIER C

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“…Obtaining higher SNR via higher static magnetic field strength has drawbacks, such as increased tissue heating, nausea, and challenges in maintaing uniform fields over large regions [11][12][13] . For that reason, alternative methods based on metamaterial structures [14][15][16][17][18] , have been proposed to improve the sensitivity of MRI scans without increasing the static field strength. These include split ring resonators 19 , swiss rolls 20 , curved wire mediums 21 and spiral shape coils 22 , as well as metamaterial resonators previously reported by the authors 23,24 .…”

Section: A Smart Switching System To Enable Automatic Tuning and Detuning Of Metamaterials Resonators In Mri Scansmentioning

confidence: 99%

A smart switching system to enable automatic tuning and detuning of metamaterial resonators in MRI scans

Saha

Pricci

Κουτσουπίδου

et al. 2020

Sci Rep

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We present a radio-frequency-activated switching system that can automatically detune a metamaterial resonator to enhance magnetic resonance imaging (MRI) performance. Local sensitivity-enhancing metamaterials typically consist of resonant components, which means that the transmitted radio frequency field is spatially inhomogeneous. The switching system shows for the first time that a metamaterial resonator can be detuned during transmission and tuned during reception using a digital circuit. This allows a resonating system to maintain homogeneous transmit field while maintaining an increased receive sensitivity. As a result, sensitivity can be enhanced without changing the system-provided specific absorption rate (SAR) models. The developed digital circuit consists of inductors sensitive to the transmit radio-frequency pulses, along with diodes acting as switches to control the resonance frequency of the resonator. We first test the automatic resonator detuning on-the-bench, and subsequently evaluate it in a 1.5 T MRI scanner using tissue-mimicking phantoms. The scan results demonstrate that the switching mechanism automatically detunes the resonator in transmit mode, while retaining its sensitivity-enhancing properties (tuned to the Larmor frequency) in receive mode. Since it does not require any connection to the MRI console, the switching system can have broad applications and could be adapted for use with other types of MRI scanners and field-enhancing resonators.

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“…18 The image quality has been enhanced using metamaterial absorber inspired energy harvester with DC-AC conversion using lumped components. 19 Multiband absorption with broader adaptability, compact profile and greater angular stability is needed for practical usage.…”

Section: Introductionmentioning

confidence: 99%

Compact polarisation insensitive wide angular stable triple band absorber for RF energy harvesting, RCS reduction, and sensor applications

Shukoor

Kumar

Dey

2021

Int J RF Microw Comput Aided Eng

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This paper presents a new compact ultra-thin triple-band absorber which shows near-unity absorption in C, X and Ku-bands. It consists of an inductive stub loaded circular ring resonator and a flower-shaped resonating patch on top of 0.8 mm thin FR-4 grounded dielectric substrate. A transmission line equivalent is proposed, and circuit simulation response is in good agreement with the full-wave analysis. The unit-cell architect's 4fold symmetry makes it polarisation-insensitive for different polarisation angles in the azimuthal plane (? = 0 ) under normal incidence. Its good shows angular stability up to 45 under TE (75 under TM) incidences for all three frequencies. Surface current patterns are analysed at resonant frequencies to illustrate the mechanism behind the electromagnetic absorption. This design's novelty lies in the centre patch's dual-resonating behaviour, making this design compacted one. The absorber has low-profile nature with cell periodicity of 0.163λ L and thickness 0.013λ L , where λ L is the lowest resonating peak wavelength. An X-band conventional MSA is fabricated on a thin FR-4 substrate. In-band RCS reduction (nearly 18 dBsm) of the antenna is verified after loading with the proposed absorber. The absorptivity peaks are optimised such that the same structure would be used in different applications like RF energy harvesting, RCS reduction and sensor applications.

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Enhancement of image quality by using metamaterial inspired energy harvester

Cited by 45 publications

References 26 publications

Double-Elliptical Shaped Miniaturized Micro Strip Patch Antenna for Ultra-Wide Band Applications

Double-Elliptical Shaped Miniaturized Micro Strip Patch Antenna for Ultra-Wide Band Applications

A smart switching system to enable automatic tuning and detuning of metamaterial resonators in MRI scans

Compact polarisation insensitive wide angular stable triple band absorber for RF energy harvesting, RCS reduction, and sensor applications

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