Measuring the Permittivity of Dielectric Materials Using STDR Approach

Moradi, Gholamreza; Abdipour, Abdolali

doi:10.2528/pier07080201

Cited by 19 publications

(14 citation statements)

References 8 publications

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“…It should be noted that in study [11] On the other hand, the experimental validation remains very limited by the available techniques for measuring the electromagnetic properties of human tissues, even though lately some approaches have been developed for measurement of permittivity of complex tissues that might be used, to some extent, and for biological tissues [21][22][23][24][25].…”

Section: Ghzmentioning

confidence: 99%

Derivation of Electromagnetic Properties of Child Biological Tissues at Radio Frequencies

Ibrani

Ahma²,

Hamiti³

et al. 2011

PIER Letters

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Abstract-The knowledge of electromagnetic properties of biological tissues is required to assess the radio frequency energy deposition in children exposed to electromagnetic fields. The issue whether children should be considered a dosimetric sensitive group in comparison to adults, to which the confirmation of age-dependence of human tissue electromagnetic properties potentially may contribute remains debatable at scientific forums. This paper derives the formula for calculation of electromagnetic properties (permittivity and conductivity) of children tissues, as a function of height, weight, and age, respectively. By using the proposed formula, we have calculated and presented electromagnetic properties of the muscle, brain (gray matter) and skin for 1-year-old to 10-year-old children for 900 MHz, 1800 MHz and 2.4 GHz, at which frequencies most of radio frequency devices used by children operate. The trend over the age of child electromagnetic properties has been presented, and electromagnetic properties at different frequencies for the same child age have also been compared. For certain tissues, comparison between the children at various age and adult electromagnetic parameters has been given. A database with electromagnetic properties for children, of all ages, tissues and frequencies may be built up with the proposed approach. It will further advance research on the assessment of children exposure to electromagnetic fields. Formula can also be used for the determination of electromagnetic parameters for children with specific height and weight.

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Section: Ghzmentioning

confidence: 99%

Derivation of Electromagnetic Properties of Child Biological Tissues at Radio Frequencies

Ibrani

Ahma²,

Hamiti³

et al. 2011

PIER Letters

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“…Pulse propagation in inhomogeneously filled guides has received far less attention [9,10], even though partially-filled guides are often used for determining the constitutive parameters of material samples [11][12][13][14][15]. Recently, Moradi and Abtipour [16] proposed using time-domain methods to extract the material parameters of waveguide samples. Such approaches require an understanding of the interaction of propagating transient fields with the interfaces between differing materials.…”

Section: Introductionmentioning

confidence: 99%

Pulse Reflection From a Dielectric Discontinuity in a Rectangular Waveguide

Rothwell¹,

Temme²,

Crowgey³

2009

PIER

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Abstract-A simple, closed-form expression for the time-domain reflection coefficient for a pulsed TE 10 -mode wave incident on a dielectric material discontinuity in a rectangular waveguide is presented. This formula may be used to represent the transient field reflected or transmitted by a dielectric-filled waveguide section, which is useful in material characterization routines. An exponential function approximation to the reflection coefficient is presented, and the formula is validated both numerically and experimentally.

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“…Transmission-reflection and reflection-only non-resonant methods have been widely utilized for characterization of materials owing to their relative simplicity, broad frequency coverage, and higher accuracy [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. There are few problems of these methods such as undesired ripples in the measured parameters, the increased uncertainty in referenceplane positions, and multiple solutions for electromagnetic parameters.…”

Section: Introductionmentioning

confidence: 99%

Resolving Phase Ambiguity in the Inverse Problem of Reflection-Only Measurement Methods

Hasar¹,

Barroso²,

Sabah³

et al. 2012

PIER

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Abstract-We have applied the phase unwrapping technique to resolve the phase ambiguity problem arising from complex expressions of scattering parameters, for reflection-only measurement configurations, since, at some instances, only one side of the sample under test is accessible for electromagnetic measurements. We considered two different measurement configurations for testing the applicability of the phase unwrapping technique as: 1) two identical samples with different lengths flushed by a short-circuit termination and 2) one sample shorted by a varying short-circuit termination. For each measurement configuration, the underlying expressions for the reflection scattering parameters are derived. For both cases, we evaluated the suitability of the phase unwrapping technique by considering a highly-dispersive medium (distilled water) as our test sample. We note that continuity of the real part of the complex wavelength is a key issue in the unwrapping technique for (one-port) reflection-only measurements.

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Measuring the Permittivity of Dielectric Materials Using STDR Approach

Cited by 19 publications

References 8 publications

Derivation of Electromagnetic Properties of Child Biological Tissues at Radio Frequencies

Derivation of Electromagnetic Properties of Child Biological Tissues at Radio Frequencies

Pulse Reflection From a Dielectric Discontinuity in a Rectangular Waveguide

Resolving Phase Ambiguity in the Inverse Problem of Reflection-Only Measurement Methods

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