As a technique for calibrating electric-field probes used in standardized SAR (Specific Absorption Rate) assessment, we have studied the technique using the Friis transmission formula in the tissue-equivalent liquid. It is difficult to measure power transmission between two reference antennas in the far-field region due to large attenuation in the liquid. This means that the conventional Friis transmission formula cannot be applied to our measurement so that we developed an extension of this formula that is valid in the near-field region. In this paper, the method of weighted least squares is introduced to reduce the effect of the noise in the measurement system when the gain of the antenna operated in the liquid is determined by the curve-fitting technique. And we examine how to choose the fitting range to reduce the uncertainty of the estimated gain.
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Nozomu ISHII, Hiroki SHIGA, Naoto IKARASHI, Ken-ichi SATO, Lira HAMADA, Soichi WATANABE, "Simultaneous Measurement of Antenna Gain and Complex Permittivity of Liquid in Near-Field Region Using Weighted Regression" in IEICE TRANSACTIONS on Communications,
vol. E91-B, no. 6, pp. 1831-1837, June 2008, doi: 10.1093/ietcom/e91-b.6.1831.
Abstract: As a technique for calibrating electric-field probes used in standardized SAR (Specific Absorption Rate) assessment, we have studied the technique using the Friis transmission formula in the tissue-equivalent liquid. It is difficult to measure power transmission between two reference antennas in the far-field region due to large attenuation in the liquid. This means that the conventional Friis transmission formula cannot be applied to our measurement so that we developed an extension of this formula that is valid in the near-field region. In this paper, the method of weighted least squares is introduced to reduce the effect of the noise in the measurement system when the gain of the antenna operated in the liquid is determined by the curve-fitting technique. And we examine how to choose the fitting range to reduce the uncertainty of the estimated gain.
URL: https://global.ieice.org/en_transactions/communications/10.1093/ietcom/e91-b.6.1831/_p
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@ARTICLE{e91-b_6_1831,
author={Nozomu ISHII, Hiroki SHIGA, Naoto IKARASHI, Ken-ichi SATO, Lira HAMADA, Soichi WATANABE, },
journal={IEICE TRANSACTIONS on Communications},
title={Simultaneous Measurement of Antenna Gain and Complex Permittivity of Liquid in Near-Field Region Using Weighted Regression},
year={2008},
volume={E91-B},
number={6},
pages={1831-1837},
abstract={As a technique for calibrating electric-field probes used in standardized SAR (Specific Absorption Rate) assessment, we have studied the technique using the Friis transmission formula in the tissue-equivalent liquid. It is difficult to measure power transmission between two reference antennas in the far-field region due to large attenuation in the liquid. This means that the conventional Friis transmission formula cannot be applied to our measurement so that we developed an extension of this formula that is valid in the near-field region. In this paper, the method of weighted least squares is introduced to reduce the effect of the noise in the measurement system when the gain of the antenna operated in the liquid is determined by the curve-fitting technique. And we examine how to choose the fitting range to reduce the uncertainty of the estimated gain.},
keywords={},
doi={10.1093/ietcom/e91-b.6.1831},
ISSN={1745-1345},
month={June},}
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TY - JOUR
TI - Simultaneous Measurement of Antenna Gain and Complex Permittivity of Liquid in Near-Field Region Using Weighted Regression
T2 - IEICE TRANSACTIONS on Communications
SP - 1831
EP - 1837
AU - Nozomu ISHII
AU - Hiroki SHIGA
AU - Naoto IKARASHI
AU - Ken-ichi SATO
AU - Lira HAMADA
AU - Soichi WATANABE
PY - 2008
DO - 10.1093/ietcom/e91-b.6.1831
JO - IEICE TRANSACTIONS on Communications
SN - 1745-1345
VL - E91-B
IS - 6
JA - IEICE TRANSACTIONS on Communications
Y1 - June 2008
AB - As a technique for calibrating electric-field probes used in standardized SAR (Specific Absorption Rate) assessment, we have studied the technique using the Friis transmission formula in the tissue-equivalent liquid. It is difficult to measure power transmission between two reference antennas in the far-field region due to large attenuation in the liquid. This means that the conventional Friis transmission formula cannot be applied to our measurement so that we developed an extension of this formula that is valid in the near-field region. In this paper, the method of weighted least squares is introduced to reduce the effect of the noise in the measurement system when the gain of the antenna operated in the liquid is determined by the curve-fitting technique. And we examine how to choose the fitting range to reduce the uncertainty of the estimated gain.
ER -