Journal ArticleDOI
Effects on portable antennas of the presence of a person
TLDR
This work has shown how input impedance, far-field radiation pattern, radiation efficiency, and the magnitude of the near field are affected by the presence of the human body.Abstract:
This work deals with the influence the presence of a person has on the performance of antennas for hand-held portable telephones. It is shown how input impedance, far-field radiation pattern, radiation efficiency, and the magnitude of the near field are affected by the presence of the human body. The investigations have been carried out by applying the finite-difference time-domain (FDTD) technique to a model of the telephone with a lambda /4 monopole antenna and a simple hand-head model of the operator. Results from this configuration are compared with results for the telephone box and antenna alone. Measurements have been performed to verify the results obtained by simulations. The results show that a shadow effect in the far-field pattern occurs in the direction of the person and that the radiation pattern, including polarization, changes considerably from the telephone with the antenna alone. The impedance results show a change in resonance frequency when the telephone is placed next to a person. Results for radiation efficiency show that close to half of the energy is absorbed by hand and head. On average a system loss of 3-4 dB should be included in a link budget, and there is considerable fading, even in a radio-anechoic chamber, when persons move around in a natural manner. >read more
Citations
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Journal ArticleDOI
EM interaction of handset antennas and a human in personal communications
TL;DR: In this article, the authors investigated the effect of the tissue location and physical model on the antenna performance and found that the head and hand absorb between 48 and 68% of the power delivered to the antenna.
Journal ArticleDOI
Dual-frequency planar inverted-F antenna
Zi Dong Liu,Peter Hall,D. Wake +2 more
TL;DR: In this paper, the authors proposed a planar dual-band inverted-F antenna for cellular handsets, which operates at the 0.9-GHz and 1.8-GHz bands.
Journal ArticleDOI
A study of the handset antenna and human body interaction
M. Okoniewski,M.A. Stuchly +1 more
TL;DR: In this article, computer tomography (CT) and magnetic resonance imaging (MRI)-derived, high-resolution models of the human head are used to analyze the antenna radiation pattern and other characteristics.
Journal ArticleDOI
SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz.
P J Dimbylow,Simon Mann +1 more
TL;DR: Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) have been performed on this model with a 2 mm resolution for a generic mobile communication transceiver represented by a quarter-wavelength monopole on a metal box.
Journal ArticleDOI
Specific absorption rate and temperature increases in the head of a cellular-phone user
TL;DR: In this article, a complete electromagnetic and thermal analysis has been performed considering the head of a subject exposed to various kinds of cellular phones available on the market, and focusing the attention on important organs like the eye lens and brain.
References
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Journal ArticleDOI
Performance Analysis of a Built-In Planar Inverted F Antenna for 800 MHz Band Portable Radio Units
T. Taga,Koichi Tsunekawa +1 more
TL;DR: The pattern averaging gain (PAG) method to estimate the average gain of mobile antennas in a multipath propagation environment is proposed and the antenna configuration with the PIFA element mounted on the lateral side of the radio case is found to be most suitable for portable radio units.
Journal ArticleDOI
Antennas for VHF/UHF personal radio: A theoretical and experimental study of characteristics and performance
Jørgen Bach Andersen,F. Hansen +1 more
TL;DR: In this paper, a theoretical analysis of the characteristics of small personal radio antennas for the 68- to 470-MHz frequency range is given, and the influence of the body on the performance of the antenna is investigated in detail.
Journal ArticleDOI
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Q. Balzano,O. Garay,F.R. Steel +2 more
TL;DR: In this article, the measured values of energy deposited in simulated human tissue exposed for one minute in the immediate vicinity of 800 MHz portable radio transmitters are presented, and the deposited RF energy was evaluated by temperature measurements.
Journal ArticleDOI
Retarded time absorbing boundary conditions
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TL;DR: In this article, a formulation of the boundary problem using retarded time values of the field inside the computational domain is suggested, and hence the name retarded time absorbing boundary condition (RT-ABC).