Permittivity Measurements at Microwave Frequencies Using Lumped Elements

Stuchly, S.S.; Rzepecka, Maria A.; Iskander, Magdy F.

doi:10.1109/tim.1974.4314218

Cited by 84 publications

(25 citation statements)

References 7 publications

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“…The launched power into the first segment of 45-km standard fiber was P s ϭ 8 dBm. After the first span, the signal was simultaneously phase conjugated and amplified using a fiber-optic parametric amplifier (FOPA) consisting of 5-km DSF with an average zero-dispersion wavelength at 0 Х 1558.15 nm (measured with the method described in [7]), dispersion slope S 0 ϭ 0.07 ps/nm-km, and nonlinear coefficient ␥ ϭ 2.2 (km-W)…”

Section: Introductionmentioning

confidence: 99%

“…Also, human tissue samples were studied at microwave frequencies by Cook [5] and Land et al [6]. Sample cell-terminated transmission-line methods have obtained good response at lower microwave frequency, but the accuracy is very much comprised at higher microwave frequencies [5,7,8]. The open-ended coaxial-line method allows measure- ments in a wide range of frequencies [9,10].…”

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confidence: 99%

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Dielectric properties of human urine at microwave frequencies

Lonappan

Hamsakkutty

Bindu

et al. 2004

Micro & Optical Tech Letters

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fabricated by us. Figures 5 and 6 show the results for the two kinds of fibers, respectively. The FSR is about 8.06 nm for the PANDA-PMF of length 761 mm in Figure 5. Meanwhile, the FSR is about 1.05 nm for the PCF of length 564 mm as shown in Figure 6.2 /⌬L values for the PANDA-PMF and the PCF are about 3.8 ϫ 10 Ϫ4 and 3.9 ϫ 10 Ϫ3 at 1545 nm wavelength, respectively. It is clear that, compared with 2 /⌬L, d(n x Ϫ n y )/d is small, and can be ignored in our PCF case. Thus, from Eqs. (1) and (3), the birefringences are ϳ3.8 ϫ 10 Ϫ4 and ϳ3.9 ϫ 10 Ϫ3 at the 1545-nm wavelength for the PANDA-PMF and the PCF, respectively, and the beat lengths L B are about 3.6 mm and 0.33 mm, respectively.Our asymmetric core design for highly birefringent PCF is similar to the one proposed in [4]. The difference is only the intentional stress-induced birefringence added in the fabrication process. In [4], the expected value of birefringence for hole size d/⌳ of 0.431 and normalized frequency ⌳/ of ϳ3.76 was below 1.0 ϫ 10 Ϫ4. It is clear that our experimental value is one order of magnitude higher than the theoretical value in [4] CONCLUSIONIn conclusion, we have designed and fabricated a photonic-crystal fiber with a high birefringence by utilizing the asymmetric core design and intentional stress-induced anisotropy. A short beat length of 0.33 mm at 1545 nm was observed for the PCF. Birefringence of the PCF was improved to one order of magnitude higher than the value reported by T.P. Hansen et al. [4]. INTRODUCTIONMicrowave engineering has been rendering important contributions to both diagnostic and therapeutic medicine. Clinical investigation plays a vital role in the diagnosis of disease for medical practioners to reach conclusive decisions after procedures such as inspection, palpation, and percussion. A number of medical devices, which uses microwaves, were developed for biomedical applications [1]. Exhaustive studies of dielectric parameters of various human tissues at different RF frequencies were reported by Gabriel et al. [2, 3]. Dielectric parameters of human blood at microwave frequencies using coaxial line and the waveguide method were reported by Cook [4]. Also, human tissue samples were studied at microwave frequencies by Cook [5] and Land et al. [6]. Sample cell-terminated transmission-line methods have obtained good response at lower microwave frequency, but the accuracy is very much comprised at higher microwave frequencies [5,7,8]. The open-ended coaxial-line method allows measure- ments in a wide range of frequencies [9,10]. Standard waveguide dielectric samples allow measurements in the entire microwave region with a good degree of accuracy, except at lower frequencies where the sample size is very large [11]. Microwave medical tomography is emerging as a novel nonhazardous method of imaging for the detection of fracture, swelling, and diagnosis of tumors. For active and passive microwave imaging for disease detection and treatment, monitoring requires proper knowledge of the dielectric properties of body ...

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Dielectric properties of human urine at microwave frequencies

Lonappan

Hamsakkutty

Bindu

et al. 2004

Micro & Optical Tech Letters

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“…where θ = 90 • , ω = 2π f , C o = ε o S/(0.5 mm) and Z o = 50 [8]. Figure 5 shows the log plot of ε r versus l at 9.4 GHz.…”

Section: Reflection Intensity and Reflection Coefficient Of Alo And Stomentioning

confidence: 99%

Dielectric measurement using non-contact microwave single probe for dielectric materials

et al. 2006

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A high frequency dielectric measurement method was proposed using a non-contact probe. The microwave reflection intensity was measured for Al 2 O 3 and SrTiO 3 substrates at room temperature as a function of distance between sample and probe. The difference of reflection intensity for Al 2 O 3 and SrTiO 3 substrates was observed in the region where the distance of 0.2 mm between sample and probe, and it was caused from dielectric permittivities of samples. The reflection coefficient of sample was estimated in comparison with results of electromagnetic simulation. The reflection intensity for Al 2 O 3 and SrTiO 3 substrates was transformed to dielectric permittivity at reflection intensity minimum point.

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“…The transmission structures range from rectangular waveguide [3] to coaxial line [4] or stripline [5], among which transmitting parameters like propagation constants or S parameters are measured. All of these methods have in common that dielectric parameters are calculated explicitly from given formulas at microwave frequencies.…”

Section: Introductionmentioning

confidence: 99%

A Corrected Method to Extract Dielectric Parameters From Transmission Lines With Conductor Surface Roughness at Terahertz Frequencies

Huang¹,

Jia²,

Wang³

2017

PIER M

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Abstract-"Curve-fitting" method is an important method to extract dielectric parameters of substrate materials from planar transmission lines. At gigahertz frequencies, effective conductivity concept is adopted to model the conductor's surface roughness effects in planar transmission lines, and differential extrapolation method is used to remove surface roughness effects. However, such a concept and method lose their accuracy at extremely high frequency such as terahertz waves. This paper details some new limitations in the terahertz regime and proposes corrections in calculating effective conductivity with rough conductor and curve-fitting method for transmission performance characterization in eliminating the effects of surface roughness. The proposed method is validated by simulation data for conductivity with parallel plate waveguide model, and the corrected method presented here can effectively extract dielectric parameters with an error less than 7%.

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Permittivity Measurements at Microwave Frequencies Using Lumped Elements

Cited by 84 publications

References 7 publications

Dielectric properties of human urine at microwave frequencies

Dielectric properties of human urine at microwave frequencies

Dielectric measurement using non-contact microwave single probe for dielectric materials

A Corrected Method to Extract Dielectric Parameters From Transmission Lines With Conductor Surface Roughness at Terahertz Frequencies

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