Conclusions
[6] N. Kuster and Q. Balzano, "Energy Absorption
Mechanism by Biological Bodies in the Near Field of
Dipole Antennas Above 300 MHz." IEEE Trans. On
Vehicular Technology, vol. 41, no.1, Feb. 1992, pp. 17-
Our research demonstrates very good agreement
23.
between a theoretical numerical model and an actual
physical dipole experiment. The interaction of the tissue
[7] IEC 62209, IEEE1528.
properties on the dipoles electrical performance is well
studied and repeatable. We have demonstrated the
[8] Kunz K S, and Luebbers R J, "The Finite Difference
application of the Chebychev matching methods of
Time Domain Method for Electromagnetics", CRC
previous research, and put them into practice. Results
Press, 1993.
can be used for the determination of SAR target
numbers related to exposure of simulated human tissue
[9] J.J. Wojcik and T. Harrington "Analysis of Head
fluid specifically for the 5-6GHz frequency band.
Phantom Dimensional and Shape Relative Errors in
Experimental studies were conducted using the physical
Wireless Specific Absorption Rate (SAR) Compliance
model of the APREL Laboratories Universal Phantom
Assessment. 2001 IEEE EMC Itnl Symposium PP 1158-
figure 7 which resulted from a study into methods for
1163
reducing errors for compliance assessment Wojcik &
___
Harrington [9] and the development of the broad band
Future Activities
dipole antenna. The tissue simulation fluids used within
the experimental studies consisted of two mixtures, and
As part of the ongoing research activities APREL
the overall depth of tissue within the phantom was fixed
Laboratories with support from the Spectrum Sciences
at 10cm. The dipole was placed at a separation distance
Institute and in cooperation with Remcom (among
of 10mm (dipole centre to tissue). The dipole was
others) will work on developing a new method for
connected to a Vector Network Analyzer and assessed
simulating anatomical tissues at frequencies in the 5-
using S11 parameters for return loss, standing wave
6GHz range. The data will be made public and be
ratio, and impedance.
presented to other forums. The intention is to lead
further developments of numerical evaluations for
The computational modeling is based on the finite-
complex dipole and tissue models.
difference time-domain analytic software (XFDTD)
provided from Remcom Inc., which was used to derive
Further research is essential for the progress of
the data for this report [8]. This paper demonstrates a
international standards covering the frequency range of
viable method to evaluate the accuracy of numerical and
5-6GHz so it is essential to have bi-lateral participation
experimental research with measurements and
and input. Activities that need further attention through
calculated data presented.
research include but are not limited to the following:
References
1.
Creation of a defined methodology and set of guide
lines for users of numerical code, where results
[1] Robert E. Collin, "Foundations for Microwave
may be used as a reference.
Engineering", McGraw-Hill, 1966, pp. 223-235.
2.
Investigation into the effects of RF sources on
tissue at frequencies above 3GHz.
[2] Theodore S. Saad, "Microwave Engineers
3.
Define experimental homogeneous models based
Handbook", Volume 2, Artech House, 1971, Optimally
on research into the effects of RF on tissues above
Matched Compensated Balun, page 51.
3GHz.
4.
The creation of stable tissue recipes for use in
[3] George Oltman, "The Compensated Balun" IEEE
frequencies above 3GHz based on scientific
Transactions on Microwave Theory and Techniques,
research, traceable back to geometrically accurate
volume MTT-14 no. 3 March 1966, pp.112-119.
heterogeneous anatomical models
[4] A. Faraone, "Towards a Low-Power Exclusion"
Motorola Labs, Presentation to IEEE SCC34-SC2,
May22, 2003, page 19 (unpublished).
[5] A. Faraone, Q. Balzano and D. Simunic,
"Experimental Dosimetry in a Sphere of Simulated
Brain Tissue Near a Half-Wave Dipole Antenna," IEEE
Int. Symp. On EMC , 1998, pp. 906-911.