Phantoms for antenna measurements at 2.4 GHz

Loader, Benjamin; Loh, Tian Hong

doi:10.1109/eucap.2012.6206191

Cited by 3 publications

(3 citation statements)

References 3 publications

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“…The TSL is made of 70.73% water, 28.33% polysorbate20 and 0.93% NaCl (by weight) and mimics the average dielectric properties of human body tissue at a frequency of 150 MHz (Loader et al 2010). Human tissue data originate from the works of Gabriel et al (Gabriel et al 1996a(Gabriel et al , 1996b(Gabriel et al , 1996c, being widely available thanks to some online databases (Andreuccetti et al 2000 andHasgall et al 2013).…”

Section: Laboratory Setupmentioning

confidence: 99%

Assessment of computational tools for MRI RF dosimetry by comparison with measurements on a laboratory phantom

et al. 2015

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This paper presents an extended comparison between numerical simulations using the different computational tools employed nowadays in electromagnetic dosimetry and measurements of radiofrequency (RF) electromagnetic field distributions in phantoms with tissue-simulating liquids at 64 MHz, 128 MHz and 300 MHz, adopting a customized experimental setup. The aim is to quantify the overall reliability and accuracy of RF dosimetry approaches at frequencies in use in magnetic resonance imaging transmit coils. Measurements are compared against four common techniques used for electromagnetic simulations, i.e. the finite difference time domain (FDTD), the finite integration technique (FIT), the boundary element method (BEM) and the hybrid finite element method-boundary element method (FEM-BEM) approaches. It is shown that FDTD and FIT produce similar results, which generally are also in good agreement with those of FEM-BEM. On the contrary, BEM seems to perform less well than the other methods and shows numerical convergence problems in presence of metallic objects. Maximum uncertainties of about 30% (coverage factor k = 2) can be attributed to measurements regarding electric and magnetic field amplitudes. Discrepancies between simulations and experiments are found to be in the range from 10% to 30%. These values confirm other previously published results of experimental validations performed on a limited set of data and define the accuracy of our measurement setup.

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Section: Laboratory Setupmentioning

confidence: 99%

Assessment of computational tools for MRI RF dosimetry by comparison with measurements on a laboratory phantom

et al. 2015

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“…A second test for robust antenna performance is to investigate how the performance varies in proximity to boundaries between different tissue types. To do this, a second numerical phantom model was generated, replicating the shape of a layered human tissue phantom developed at Queen's University Belfast [15] [16]. The nylon shell was replaced with SAT and skin layers, each with a thickness of 2 mm, making a more realistic implant boundary condition.…”

Section: Figure 1-antenna Geometrymentioning

confidence: 99%

Robust implantable antenna for in-body communications

Magill

Conway

Scanlon

2015

2015 Loughborough Antennas &Amp; Propagation Conference (LAPC)

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A compact implantable printed meandered folded dipole antenna with a volume of 101.8 mm 3 and robust performance is presented for operation in the 2.4 GHz medical ISM bands. The implant antenna is shown to maintain its return loss performance in the 2360-2400 MHz, 2400-2483.5 MHz and 2483.5-2500 MHz frequency bands, simulated in eleven different body tissue types with a broad range of electrical properties. Bandwidth and resonant frequency changes are reported for the same antenna implanted in high water content tissues such as muscle and skin as well as low water content tissues such as subcutaneous fat and bone. The antenna was also shown to maintain its return loss performance as it was moved towards a tissue boundary within a simulated phantom testbed.

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“…A simple square‐shaped liquid phantom has been already presented in [12] and a homogeneous anthropomorphic whole body liquid phantom is used for measurements in [13]. More examples of all the types of phantoms are extensively described in [5, 7, 9, 14–17].…”

Section: Introductionmentioning

confidence: 99%

Design, realisation and evaluation of a liquid hollow torso phantom appropriate for wearable antenna assessment

Tsolis

Paraskevopoulos

Alexandridis

et al. 2017

IET Microwaves, Antennas & Propagation

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This study examines the design, realisation and evaluation of a lightweight and low cost hollow oval cross‐section torso phantom appropriate for wearable antenna performance assessment. The phantom consists of an empty inner space (hollow) surrounded by a shell with double plastic walls between which there is a tissue simulating liquid. The phantom's plastic shell is made of a low loss cast acrylic and the liquid is a commercially available one with properties calibrated for the frequency range of 2–6 GHz. The proposed phantom is compared, through simulations, with a full liquid torso phantom and a heterogeneous anthropomorphic voxel phantom. In addition, the fabricated phantom is compared with human bodies and a homogeneous anthropomorphic solid phantom, through measurements. The phantom performance is tested in terms of electric field distribution of a wearable antenna on its surface and the path loss between two wearable antennas, on either side of the phantom. It is proved that the hollow phantom performance approximates the full liquid phantom when an RF absorbing material is placed in the central hollow region. The phantom performance in terms of S11 wearable antenna measurements is evaluated and found in good agreement with real human bodies in the examined frequency range (2–6 GHz). The far‐field wearable antenna performance of the proposed phantom shows deviation in gain <1.5 dB, compared with anthropomorphic phantom.

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Phantoms for antenna measurements at 2.4 GHz

Cited by 3 publications

References 3 publications

Assessment of computational tools for MRI RF dosimetry by comparison with measurements on a laboratory phantom

Assessment of computational tools for MRI RF dosimetry by comparison with measurements on a laboratory phantom

Robust implantable antenna for in-body communications

Design, realisation and evaluation of a liquid hollow torso phantom appropriate for wearable antenna assessment

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