A Method of Moments Study of Sar Inside Spheroidal Human Head and Current Distribution Along Handset Wire Antennas

Kang, Xi; Li, Le‐Wei; Leong, Mook‐Seng; Kooi, P.S.

doi:10.1163/156939301x00643

Cited by 17 publications

(13 citation statements)

References 3 publications

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“…Many studies on the SAR value of a single antenna for mobile handsets have been carried out in different frequency bands [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. In [27], an investigation of the SAR caused by two-element antenna array at 1.9 GHz has been reported and it was shown that the SAR value reaches a maximum when the phase difference is near 180 degrees and a minimum when the phase difference is approximately 0 degree.…”

Section: Introductionmentioning

confidence: 99%

An Interaction Study Between Pifas Handset Antenna and a Human Hand-Head in Personal Communications

Montaser¹,

Mahmoud²,

Elmikati³

2012

PIER B

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Abstract-In this paper, the interaction of a planar inverted-F antennas array, mounted on a mobile handset, with a human hand-head phantom is investigated in the 1.9 GHz band. The hybrid approach involving the particle swarm optimization (PSO) and Nelder-Mead (NM) algorithm is considered to optimize the complex excitations of the adaptive array elements in a mutual coupling environment for different beamforming synthesis. Firstly, the effect of the human handhead on the handset radiation characteristics is studied. Then, the spatial-peak specific absorption rate (SAR) values of 2-and 4-element PIFA arrays for mobile handset in the vicinity of a human handhead are evaluated numerically for different scenarios. The antenna is analyzed completely using finite difference time domain (FDTD) method while the interaction is performed using the CST Microwave Studio software.

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Section: Introductionmentioning

confidence: 99%

An Interaction Study Between Pifas Handset Antenna and a Human Hand-Head in Personal Communications

Montaser¹,

Mahmoud²,

Elmikati³

2012

PIER B

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“…Peak spatial-average SAR (specific absorption rate) is used as a metric for RF localized exposures. Many researchers have been investigated the human-antenna interactions with this metric [3][4][5][6][7][8][9][10]. However, physiological effects and damage to humans due to microwave energy would be induced by temperature elevation.…”

Section: Introductionmentioning

confidence: 99%

On Averaging Mass of Sar Correlating With Temperature Elevation Due to a Dipole Antenna

Hirata¹,

Shirai²,

Fujiwara³

2008

PIER

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Abstract-This study investigated the relationship between temperature elevation and spatial-average SAR (specific absorption rate) in a head model of a Japanese male due to a dipole antenna. The frequencies considered are in the range between 800 MHz and 3 GHz, which are used in wireless communications. Our attention focuses on the average mass of SAR which maximizes the correlation with local temperature elevation. Computational results suggested that an appropriate averaging mass of SAR did not exist over wide frequencies, which was attributed to the frequency-dependent penetration depth of electromagnetic waves. For most cases considered in this study the SAR averaging over 10 g was better than that for 1-g from the standpoint of correlating the temperature elevation. The dominant factor influencing this averaging mass is the thermal diffusion length which largely depends on the blood perfusion rate. Additionally, the heat evolved in the pinna played an important role in the correlation between spatialaverage SAR and temperature elevation.

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“…Although spherical head models may appear to be rather simplistic compared to the anatomically detailed models, they have been widely used and are still being used in dosimetric studies, e.g., [31,32]. In this context, Green/MoM technique advantageously provides a means (a) to reproduce the absorption characteristics, being exempt from the uncertainties of the FDTD method, (b) to study the impact of variation of the essential parameters of interest, (c) to easily reveal the relative RF energy source position, (d) to isolate the SAR dependence purely on volume, and (e) to provide a reliable reference to experimental measurements.…”

Section: Description Of Exposure Scenarios and Computational Methodsmentioning

confidence: 99%

Parametric Study of Power Absorption Patterns Induced in Adult and Child Head Models by Small Helical Antennas

Christopoulou¹,

Koulouridis²,

Nikita³

2009

PIER

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Abstract-A comparative assessment of power absorption in adult and child heads exposed to a small helical antenna at 1710 MHz, is presented, emphasizing the effect of age related parameters. Finite Difference Time Domain simulations are employed to study the interaction between MRI-based head models and a mobile communication terminal equipped with a small helical monopole. A semi-analytical method, based on Green's function theory and the Method of Moments, is used to study the absorption in threelayer spherical head models exposed to a small helical dipole. SAR patterns in child head models derived by non-uniform scaling of adult ones were assessed against SAR patterns computed in child heads derived by uniform downscaling procedures. In both realistic and canonical exposure scenarios, comparable levels of absorbed power Corresponding author: K. S. Nikita (knikita@cc.ece.ntua.gr). 50Christopoulou, Koulouridis, and Nikita (maximum difference: 12%) in adult and child head models were observed. Dependence of SAR values upon separation distance and tissue dielectric properties was quantitatively assessed. In realistic exposure scenarios, the reduction in peak SAR values was 60-80% for a 1 cm increase in distance and up to 16% for a 110% to 90% decrease in dielectric properties values with reference to the nominal value of 100%. These trends were respectively less (55-65%) and more (up to 24%) emphasized in the corresponding canonical exposure scenarios.

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A Method of Moments Study of Sar Inside Spheroidal Human Head and Current Distribution Along Handset Wire Antennas

Cited by 17 publications

References 3 publications

An Interaction Study Between Pifas Handset Antenna and a Human Hand-Head in Personal Communications

An Interaction Study Between Pifas Handset Antenna and a Human Hand-Head in Personal Communications

On Averaging Mass of Sar Correlating With Temperature Elevation Due to a Dipole Antenna

Parametric Study of Power Absorption Patterns Induced in Adult and Child Head Models by Small Helical Antennas

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