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Showing papers on "Relative permittivity published in 1985"


Journal ArticleDOI
TL;DR: It appears that chiral spheres are the most effective objects in retarding the progress of an incident plane wave regardless of its polarization.
Abstract: A procedure based on the T-matrix method is devised to study the electromagnetic response of chiral, (lossy) dielectric, nonspherical objects exposed to an arbitrary incident field. Reductions in the method for axisymmetric objects are discussed. Using the technique thus developed, the plane wave scattering and absorption characteristics of lossy dielectric, axisymmetric scatterers (spheres as well as prolate and oblate spheroids), with and without chiral properties, are examined at frequencies above 50 GHz. The relative permittivity of the objects is assumed to be frequency dependent, whereas the chiral parameters are set to be constant in the numerical study. From the computed results, it appears that chiral spheres are the most effective objects in retarding the progress of an incident plane wave regardless of its polarization.

135 citations


Journal ArticleDOI
01 Jan 1985
TL;DR: In this paper, the authors compared the Mach-Zehnder-IMPATT spectrometer with the openresonator and compared the open-resonators with a polarizing interferometer, showing that the dielectric loss increases with frequency in the millimeter.
Abstract: It is no longer necessary to use extrapolated microwave dielectric values when designing millimeter-wave components and systems. Very recently, highly accurate millimeter-wave (5- to 1/2-mm) data on complex dielectric permittivity and loss tangent have become available to engineers for a variety of materials such as common ceramics, semiconductors, crystalline, and glass materials. One quasi-optical measurement method has proved to be most accurate and reproducible, namely, dispersive Fourier transform spectroscopy (DFTS) applied to a polarizing interferometer. The openresonator method and the Mach-Zehnder-IMPATT spectrometer will also be described and compared. The fact that the dielectric loss increases with frequency in the millimeter, unlike the microwave, is an important feature of these data. Reliable measurements also reveal that the methods of preparation of nominally identical specimens can change the dielectric losses by a factor of three.

128 citations


Journal ArticleDOI
TL;DR: In this paper, the relative dielectric permittivity of the formation at very high and ultra-high radio frequencies is measured, and an interpretation formula is proposed to quantify the oil saturation in the formation, which is difficult to apply in situations where the water resistivity is variable or unknown as a result of water, steam, or chemical flooding.
Abstract: Conventional resistivity and induction tools measure the electrical conductivity of the formation. Interpretation of these logs is difficult in situations where the formation water resistivity is variable or unknown as a result, for example, of water, steam, or chemical flooding. Recent introduction of several dielectric tools offers a new technique in well logging. These sondes measure the relative dielectric permittivity of the formation at very‐high and ultra‐high radio frequencies. Because water has a much higher relative dielectric permittivity (about 80) than oil (about 2) or gas (about 1), the dielectric tool can distinguish hydrocarbon‐bearing zones from water‐bearing zones even when the formation fluid is nonconducting. However, in order to quantify the oil saturation in the formation, one needs an accurate formula that can relate the measured relative dielectric permittivity of the rock to the oil saturation in the rock. Present interpretation formulas have only a limited range of applicability....

105 citations


Journal ArticleDOI
TL;DR: Complex resistivity was measured for samples of Westerly granite and Berea sandstone saturated with 0.01 M KClaq as discussed by the authors, and the electrical response was analyzed in terms of equivalent conductivity σ′ and relative permittivity K′.
Abstract: Complex resistivity was measured for samples of Westerly granite and Berea sandstone saturated with 0.01 M KClaq. A four-electrode technique was employed to make measurements over a frequency range of 10−3 to 106 Hz and a confining pressure range of 0.2 to 200 MPa. When the electrical response was analyzed in terms of equivalent conductivity σ′ and relative permittivity K′, both of these quantities varied more with confining pressure for the granite samples than they did for the sandstone. In addition, both rock types exhibited large low-frequency dispersion of permittivity. While previous studies have measured the response of near-dc conductivity to changes in pressure, measurements of pressure dependence of the full complex resistivity ρ*(ω) provide greater insight into earthquake-related phenomena as well as induced polarization measurements and other remote sensing techniques.

99 citations


Journal ArticleDOI
TL;DR: Pb (Mg 1 3, Nb 2 3 ) O 3 perovskite type compound which can be sintered at low temperatures has a ligh dielectric permittivity and so can be used as multilayer ceramic capacitors as discussed by the authors.

51 citations


Journal ArticleDOI
TL;DR: In this article, a high-frequency contactless detector is described and its properties (reproducibility, stability and dependence of the sensitivity on the concentration or conductivity and relative permittivity of the measured solutions) are demonstrated and its applicability to capillary isotachophoresis is illustrated.

49 citations


Journal ArticleDOI
TL;DR: In this paper, the separated electrostriction tensor components have been measured for single crystal calcium fluoride by the converse effect, using a specially designed uniaxial elastic stressing jig.
Abstract: The separated electrostriction tensor components have been measured for single‐crystal calcium fluoride by the converse effect, using a specially designed uniaxial elastic stressing jig. Values obtained for the individual components of the electrostrictive voltage (M) coefficients were M11=−0.132, M12=0.117, and M44=0.507 in units of 10−20 m2/V2. These values are smaller than those observed by direct measurement of electric‐field‐induced elastic strain (K. Rittenmyer, Ph.D. thesis, The Pennsylvania State University, 1984), but are closer to expected values and likely to be more reliable.

21 citations


Journal ArticleDOI
TL;DR: In this paper, a ceramic dielectric, based on a Ba, Ti and (Mg1/3Nb2/3)-substituted Pb(Zn 1/3 Nb 2/3)O3 system, for multilayer ceramic capacitor (MLC) was developed according to Y5U specifications in the EIA (Electronic Industries Association) standard.
Abstract: A ceramic dielectric, based on a Ba, Ti and (Mg1/3Nb2/3)-substituted Pb(Zn1/3Nb2/3)O3 system, for multilayer ceramic capacitor (MLC) has been developed according to Y5U specifications in the EIA (Electronic Industries Association) standard. This ceramic dielectric, fired at 1000–1050°C, exhibits a 12000 relative dielectric constant, a 1.0% dissipation factor, a 30000 ΩF CR product (capacitance×resistance) at 25°C and a 10000 ΩF CR product at 85°C, respectively. An MLC using this dielectric and 70 Ag/30 Pd internal electrodes, has a small capacitance change of -30% at 1 kV/mm and a high breakdown voltage of 40 kV/mm. Capacitance temperature change is within -48% from -30 to +85°C. This dielectric is a promising candidate for use as a replacement for conventional barium titanate based dielectric for MLC.

21 citations


DOI
01 Feb 1985
TL;DR: In this paper, a measuring system for determining the complex permittivity of low-loss solids using a frequency-tuned TE01 cavity resonator of fixed length is described.
Abstract: A measuring system for determining the complex permittivity of low-loss solids using a frequencytuned TE01 cavity resonator of fixed length is described. Its mechanical construction is simple, and measurements, in particular of the real part e' of the permittivity, can be performed within a relatively short measuring time with high precision ($$$|Δe'/e'| < 7 × 10 -4 ), for a large number of frequencies in a given frequency band. The method is compared with the standard method where a length-tuned resonator is involved. Theoretical error investigations and practical measurements at frequencies of about 10 GHz on polymers and fused silica are carried out showing that the uncertainties have comparable values in both methods.

17 citations


Journal ArticleDOI
TL;DR: In this paper, the dielectric permittivity of the 4n-pentylphenyl-4n-n-octyloxythiobenzoate (8S5) was measured in the radio frequency range and at one microwave frequency of 9.38 GHz.
Abstract: Measurements of the complex dielectric permittivity for the isotropic, nematic and smectic phases (SA and SC) of the 4-n-pentylphenyl-4-n-octyloxythiobenzoate (8S5) have been performed in the radio frequency range and at one microwave frequency of 9.38 GHz. The dielectric anisotropy of 8S5 is positive in both the radio and microwave frequency regions. However, in the smectic C phase there is a change of sign of the dielectric anisotropy which might be connected with dipole-dipole correlations. The low frequency relaxation process exhibits a Debye-type behaviour in all liquid-crystalline phases. The temperature dependence of the dielectric relaxation time will be discussed in terms of the Arrhenius law.

15 citations


Journal ArticleDOI
TL;DR: In this article, the relative dielectric constant of soil using a four probe method to preclude possible errors due to polarization effects at the electrodes is reported. But the results indicate that polarization is not responsible for the high values of dielectrics reported previously by other workers.
Abstract: Measurements of the relative dielectric constant of soil using a four probe method to preclude possible errors due to polarization effects at the electrodes are reported. Results indicate that polarization is not responsible for the high values of dielectric constant reported previously by other workers.

Journal ArticleDOI
TL;DR: Values of the relative permittivity and conductivity of the rabbit retina and lens have been measured between 10 MHz and 10 GHz over the temperature range 20 to -20 degrees C and this value agrees with that obtained previously at 37 degrees C using conventional dielectric mixture theory, but the associated margin of error is much smaller.
Abstract: Values of the relative permittivity and conductivity of the rabbit retina and lens have been measured between 10 MHz and 10 GHz over the temperature range 20 to -20 degrees C. As the temperature was lowered from 20 degrees C the dielectric parameters changed smoothly until -9 degrees C where freezing occurred. At this temperatures a sharp transition was observed in both conductivity and relative permittivity, the latter filling to a value of below 10 over most of the frequency range. Analysis shows that this is due to the unfreezable water, from which a value of lens hydration is calculated. This value agrees with that obtained previously at 37 degrees C using conventional dielectric mixture theory, but the associated margin of error is much smaller.

Journal ArticleDOI
TL;DR: In this article, the results of computer-aided permittivity measurements (CAPM) on moistened paper samples, exposed to strong RF fields inside a microwave cavity are monitored in real time by a microcomputer.
Abstract: This paper presents the results of computer-aided permittivity measurements (CAPM) on moistened paper samples, exposed to strong RF fields inside a microwave cavity. Permittivity measurements, sample weight, and RF power absorbed by the sample are monitored in real time by a microcomputer. From the CAPM, the permittivity values and the moisture content of the material are calculated. The effects of paper pyrolization on the permittivity measurements are examined, and a reversal in the measured dielectric parameters is observed at the 0-percent moisture level. This CAPM method is useful to examine the dielectric properties of materials critically dependent on the moisture content, for example, in food products and in the telephone wire industry where the insulating material is obtained from dried paper pulp. In addition, this CAPM technique can be applied to study the effects of thermal and RF shocks in dielectric materials such as used in high-power microwave windows or in studying the biological effects of microwave radiation using both short and long exposure cycles.

Journal ArticleDOI
TL;DR: Yoshida et al. as discussed by the authors measured the capacitance of the polar head region of planar lipid bilayers from the dependence of the impedance to the applied frequency at an intermediate range.

Journal ArticleDOI
TL;DR: In this paper, the β relaxation of poly(butyl methacrylate) was applied to calculate the real and imaginary parts of the complex dielectric permittivity starting from measurements of isothermal polarization current.
Abstract: Some years ago, Brather proposed a method for calculation of the real and imaginary parts of the complex dielectric permittivity starting from measurements of isothermal polarization current. This method shows some advantages over the Hamon method, which is normally used. Both methods are applied in this work to the β relaxation of poly(butyl methacrylate). It is concluded that, with the usual accuracy of measurement, a combination of the two methods is advisable; Hamon's method is taken to be a first approximation to that of Brather. Results following the two procedures are compared, and their respective advantages and disadvantages are discussed.

Journal ArticleDOI
TL;DR: In this paper, the authors measured the electric permittivity in the chiral smectic C phase of p-decyloxy-benzylidene-p-amino-2-methyl-butyl-cinnamte (DOBAMBC).
Abstract: Electric permittivity ∊ and its changes under the influence of DC electric field have been measured in the chiral smectic C phase of p-decyloxy-benzylidene-p-amino-2-methyl-butyl-cinnamte (DOBAMBC). It has been observed that the electric permittivity measured along the direction parallel to smectic layers increases after applying the electric field.

Journal ArticleDOI
TL;DR: In this article, the scattering of guided and non-guided modes on a dielectric cylinder is investigated for periodically bent cylinders, in which the relative permittivity changes along the cylinder radius.
Abstract: The scattering of guided modes on a dielectric cylinder is investigated for periodically bent cylinders. The graded-index cylinders, in which the relative permittivity changes along the cylinder radius, are treated. Analytical expressions for the amplitude and phase variations of the radiation cylindrical waves are found in a uniform and self-consistent way. Fibers with arbitrary values of the core and cladding index of refraction have been investigated. The general analysis of periodic and nonperiodic deformations of small amplitudes are presented and the special cases of sinusoidally and helically bent fibers, having parabolic index profiles, are considered in detail. The two types of fiber perturbations yield similar characteristics with more radiation losses resulting from a helically bent fiber. A weak inhomogeneity of relative permittivity does not effect the characteristics significantly modifying the phase, but not the amplitude variations of interacting modes. The conversion between guided and radiation modes of different polarizations is stronger in cylinders of smaller radii. The higher order modes of a uniform cylinder are scattered stronger than the lower order modes, and the radiation losses decrease with the increasing cylinder radius.

Journal ArticleDOI
TL;DR: In this paper, the authors measured dielectric permittivity and conductivity of various high loss tissues from freshly sacrificed animals using the "infinite sample" technique, which involves mounting of the sample in a rectangular waveguide system excited in the TE/sub10/ mode at 9.4 GHz.
Abstract: The present work is concerned with the measurement of dielectric permittivity and conductivity of various high loss tissues from freshly sacrificed animals. The measurement makes use of the 'infinite sample' technique which involves mounting of the sample in a rectangular waveguide system excited in the TE/sub10/ mode at 9.4 GHz. A more complex system consisting of skin-fat-muscle combination is also studied. An evacuation of relaxation times is made in all the cases. It is hoped that these data will be relevant in further quantifying the available results in this frequency range.

Journal ArticleDOI
TL;DR: In this paper, an empirical relation for the relative permittivity in quarternary III-V semiconductor compounds is suggested as a function of composition, and the expression for the permittivities of ternary 3-V compounds can be obtained from that as a special case which is identical to that already available in the literature.
Abstract: An empirical relation for the relative permittivity in quarternary III–V semiconductor compounds is suggested as a function of composition. The expression for the permittivity of ternary III–V compounds can be obtained from that as a special case which is identical to that already available in the literature. Graphs have been plotted for static and optical permittivities against composition for the widely used quarternary semiconductor In 1- x Ga x As y P 1- y and are discussed.

Proceedings ArticleDOI
04 Jun 1985
TL;DR: In this paper, a simple, fast and fully automated method for the measurement of complex permittivities and temperature of solid or liquid samples heated by microwave absorption at 2.43 GHz, using the small perturbation technique, is described.
Abstract: A simple, fast and fully automated method for the measurement of complex permittivities and temperature of solid or liquid samples heated by microwave absorption at 2.43 GHz, using the small perturbation technique, is described. First results are discussed.

Journal ArticleDOI
TL;DR: In this article, the dielectric permittivity tensor of a liquid crystal is obtained within the model of point molecular polarizability, and the generalized Lorentz-Lorenz equations are derived in the molecular field approximation.

Journal ArticleDOI
TL;DR: In this paper, the relative permittivity and loss tangent of beryllium oxide at 99, 145, 223, and 300 K were measured at 99.9.3 GHz.
Abstract: 9.3 GHz measurement results of the relative permittivity and loss tangent of beryllium oxide at 99, 145, 223, and 300 K are reported.

Patent
25 Jan 1985
TL;DR: In this paper, the authors proposed to activate a selective ion implantation layer as a metal having no heat resistance such as Al is left as it adheres by forming a resistor thin-film on the ion insertion layer and forming a film having specific relative permittivity and thickness.
Abstract: PURPOSE:To activate a selective ion implantation layer as a metal having no heat resistance such as Al is left as it adheres by forming a resistor thin-film on the ion implantation layer and forming a film having specific relative permittivity and thickness on the thin-film and annealing the film having said permittivity and thickness. CONSTITUTION:A Ta thin-film 24 and a film 25, relative permittivity epsilontau thereof satisfies the formula of 1 layer 23 injected through the films 24, 25 while using a gate metal 26 as a mask in the substrate 21, electromagnetic waves are reflected because impedance lows in the gate metal 26 when planar electromagnetic waves 27 are projected, and electromagnetic waves are absorbed efficiently in a section to which the film 25 is attached, and activate the n layer 23 in place of heat in the Ta film 24, loss thereof is large.

Journal ArticleDOI
TL;DR: In this paper, an extension of the theory of dielectric permittivity for pure liquids was proposed for the case of the solution of a polar compound in a non-polar solvent.
Abstract: By an extension of the theory of dielectric permittivity as previously developed by the author for pure liquids, the case of the solution of a polar compound in a non-polar solvent is investigated. The substitutional model first introduced by Faber and Ziman for liquid metal alloys is shown to provide an excellent framework for the present problem, since liquid dilatation around a solute molecule has a negligible influence on the expression of the local field. The resulting formula for the dielectric permittivity is found to be in better agreement with experiment than the corresponding equation deduced from Onsager's theory.

Journal ArticleDOI
TL;DR: In this paper, the propagation of a field radiated by a vertical magnetic dipole located in a plane stratified medium is described in terms of rays obeying geometrical optics laws.
Abstract: The propagation of a field radiated by a vertical magnetic dipole located in a plane stratified medium is described in terms of rays obeying geometrical optics laws. This leads to a simple equation linking the field to the complex permittivity of each layer. This equation is then solved to obtain the real permittivity and the conductivity of each layer. In addition it is shown, by rigorously simulating measured values, that the knowledge of the phase of the field provides valuable information on the location of the interfaces.

Patent
25 Jan 1985
TL;DR: In this article, the authors proposed a method to activate a selective ion implantation layer as a metal having no heat resistance such as Al is left as it adheres by forming a film having specific relative permittivity and thickness.
Abstract: PURPOSE:To activate a selective ion implantation layer as a metal having no heat resistance such as Al is left as it adheres by forming a film having specific relative permittivity and thickness on the ion implantation layer and annealing the film CONSTITUTION:A film, relative permittivity thereof is 120pi/Zl and thickness thereof is lambda/4, is formed on the surface of a GaAs substrate 11 When planar electromagnetic waves 16 are projected, the energy of electromagnetic waves is transmitted efficiently over the lower section of the film 14, and an n region 13 is heated and activated Since the impedance of a section on which the film 14 is not attached is extremely low, impedance mismatching between said section and 120piOMEGA spatial impedance is large, the greater part of incident energy are reflected, and the temperatures of a gate metal 15 and the substrate surface 18 slightly rise Zl represents the electromagnetic wave impedance of a semiconductor to which ions are implanted selectively and lambda a wavelength The film 14 is effective when its relative permittivity epsilonr is kept within a range of the formula, and thickness may also be effective when it satisfies the formula of (2n+1)lambda/ 4(n=0,1) without being limited to lambda/4

Journal ArticleDOI
TL;DR: In this paper, the zero frequency permittivity of a suspension of conductive spherical particles in a conductive medium can be obtained by solving a purely static problem, where the dielectric increment is expressed as a function of the surface charge density which builds up on the interfaces when a time independent field is maintained in the system.
Abstract: It is shown how the zero frequency permittivity of a suspension of conductive spherical particles in a conductive medium can be obtained by solving a purely static problem. The dielectric increment is expressed as a function of the surface charge density which builds up on the interfaces when a time independent field is maintained in the system.

Journal ArticleDOI
TL;DR: In this paper, a study of dielectric permittivity and losses in glycerine, tributyrin, and tristearin in the liquid phase at frequencies from 40 Hz to 17 GHz is presented.
Abstract: Experimental equipment is described and results presented from a study of dielectric permittivity and losses in glycerine, tributyrin, and tristearin in the liquid phase at frequencies from 40 Hz to 17 GHz.

Journal ArticleDOI
TL;DR: In this paper, the complex relative permittivity of liquids of low loss was determined by an automatic precision method based on the computer-controlled measurement of the microwave power at the lower exit of a liquid-filled, inclined, standard waveguide and on a computer curve-fitting procedure.
Abstract: At frequencies of about 10 GHz, the complex relative permittivity of liquids of low loss is determined by an automatic precision method based on the computer-controlled measurement of the microwave power at the lower exit of a liquid-filled, inclined, standard waveguide and on a computer curve-fitting procedure For the real part of the permittivity, a relative uncertainty of ±00007 is achieved For the loss tangent, the uncertainty is |?tan ?| ? 11 × 10-6

Journal ArticleDOI
TL;DR: In this article, the microwave magneto-Kerr effect in semiconductors is discussed for the semiconductor being preceded by a semi-infinite dielectric and by a quarter-wave slab for both plane-wave and guided-wave cases.
Abstract: Enhancement of the microwave magneto‐Kerr effect in semiconductors is discussed for the semiconductor being preceded by a semi‐infinite dielectric and by a quarter‐wave dielectric slab for both plane‐wave and guided‐wave cases. Expressions are developed that relate the amount of the enhancement to the relative permittivity of the dielectric. Experimental results are compared to the theoretically obtained expressions for the quarter‐wave case and the experimentally obtained values compare favorably with the theory.