scholarly journals The dielectric constant of gases at ultra-high frequencies

1939 ◽  
Author(s):  
Alden Hoover Ryan
Keyword(s):  
Dielectric Constant ◽  
High Frequencies

Characterization of MgZnO Thin Film for 1 GHz MMIC Applications

2013 ◽  
Vol 832 ◽  
pp. 310-315
Author(s):  
R. Ahmad ◽  
M.S. Shamsudin ◽  
M. Salina ◽  
S.M. Sanip ◽  
M. Rusop ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Loss Tangent ◽  
Integrated Circuit ◽  
Annealing Temperature ◽  
Dielectric Material ◽  
Sol Gel ◽  
Size Reduction ◽  
High Frequencies

MgZnO thin films are proposed as a new dielectric material for 1 GHz monolithic microwave integrated circuit (MMIC) applications. The high permittivity of this material enables size reduction; furthermore this can be fabricated using a low cost processing method. In this work, MgZnO/Pt/Si thin films were synthesized using a sol-gel spin coating method. The samples were annealed at various temperatures with the effects on physical and electrical properties investigated at direct current (DC) and high frequencies. The physical properties of MgZnO thin film were analyzed using X-Ray diffraction, with the improvements shown in crystalline structure and grain size with increasing temperature up to 700 °C. DC resistivity of 77 Ωcm at higher annealing temperature obtained using a four point probe station. In order to prove the feasibility at high frequencies, a test structure consisting of a 50 Ω transmission line and capacitors with 50 × 50 μm electrode area were patterned on the films using electron beam lithography. The radio frequency (RF) properties were measured using aWiltron 37269Avector network analyzer andCascade Microtechon-wafer probes measured over a frequency range of 0.5 to 3 GHz. The dielectric constant, loss tangent and return loss, S11improve with the increment annealing temperature. The dielectric constant was found to be 18.8, with loss tangent of 0.02 at 1 GHz. These give a corresponding size reduction of ten times compared to conventional dielectrics, silicon nitride (Si3N4). These indicate that the material is suitable to be implemented as a new dielectric material for 1GHz MMIC applications.

Reduction of dielectric constant of LTCC substrates by introduction of controlled porosity

2016 ◽  
Vol 33 (3) ◽  
pp. 124-129 ◽  
Author(s):  
Beata Synkiewicz
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Internal Layers ◽  
Pore Former ◽  
Content Type ◽  
Communication Industry ◽  
High Frequencies ◽  
Microwave Electronics ◽  
Controlled Porosity ◽  
Dielectric Constant Decrease

Purpose This paper aims to present a method for the reduction of dielectric constant of low-temperature co-fired ceramics (LTCC) substrates with the use of controlled internal porosity. Design/methodology/approach A glass-ceramic green tape with addition of graphite as a pore former was developed. The green tapes were laminated and then sintered into multilayer structures with porous interior and thin external dense layers. Microstructure of green and fired structures was studied using optical and scanning microscopy. The behavior of the samples during heating was examined in a heating microscope. Impedance spectroscopy was applied for investigation of dielectric properties of the fabricated substrates. Findings Microstructure and dielectric properties of the fabricated LTCC structures were compared with the characteristics for non-porous samples with the similar composition. Introduction of 50 Wt.% admixture of graphite in the internal layers of the LTCC substrate was found to result in decrease in dielectric constant value down to about 3. Application of non-porous outer layers improved mechanical strength of the structure and smoothness of its surface, allowing screen printing of conductive pastes on both sides of the substrate. Practical implications The rapid growth of the wireless communication industry has created a great demand for the development of new and improved materials and devices operating properly at high frequencies. The fabricated materials can be useful for substrates of microwave devices. Originality/value The paper presents an innovative method of dielectric constant decrease of substrate materials. Getting insight into the phenomena responsible for formation of pores is crucial for designing materials for microwave electronics.

DIELECTRIC RELAXATION IN LIQUIDS: I. THE REPRESENTATION OF RELAXATION BEHAVIOR

1961 ◽  
Vol 39 (3) ◽  
pp. 571-594 ◽  
Author(s):  
D. W. Davidson
Keyword(s):  
Dielectric Constant ◽  
Dielectric Relaxation ◽  
Superposition Principle ◽  
Relaxation Behavior ◽  
Complex Dielectric Constant ◽  
Published Data ◽  
Relaxation Processes ◽  
High Frequencies ◽  
Arc Characteristics ◽  
The Individual

Methods are described for the determination from experimental data of the parameters used in the skewed-arc representation in the complex dielectric constant plane of dielectric relaxation in liquids. Graphs give the frequency dependence of the real and imaginary parts of the dielectric constant predicted by the skewed-arc equation. Evidence, which includes an analysis of published data and of some new data, is presented for the frequent occurrence of this type of relaxation behavior in liquids. The resolution of the effects of different relaxation processes is discussed.The recent defect-diffusion model of Glarum is found to lead, under some conditions, to complex dielectric constant loci which are practically indistinguishable from skewed-arc loci over much of the frequency range of dispersion. It predicts departures from skewed-arc behavior at relatively high frequencies which are possibly related to experimentally observed departures.It is concluded that skewed-arc characteristics arise from the presence of co-operative relaxation processes, possibly aided by the diffusion of disordered regions, in which the individual mechanisms of relaxation cannot be resolved by application of the superposition principle.

NEAR STATIONARY DIELECTRIC PROPERTIES IN HALF-METALLIC FERROMAGNETIC Ag:CrO2 NANOCOMPOSITE PARTICLES AT HIGH FREQUENCIES

2008 ◽  
Vol 22 (14) ◽  
pp. 1423-1429 ◽  
Author(s):  
G. P. SINGH ◽  
S. RAM ◽  
A. K. THAKUR
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Frequency ◽  
Power Loss ◽  
Room Temperature ◽  
Half Metallic ◽  
Nanocomposite Particles ◽  
High Frequencies ◽  
A Value ◽  
Ferromagnetic Particles

Nanocomposite particles of silver modified CrO 2 were synthesized by a chemical CrO 3 → CrO 2 reduction in the presence of Ag + in an aqueous medium whereby the half-metallic ferromagnetic particles of CrO 2 are generated within a shell of silver. The dielectric constant εr, AC resistivity ρAC, and the dielectric power loss were studied after annealing recovered Ag:CrO 2 powder (compacted as the billets), at 300°C for 2 h in air, at 10–1000 kHz frequencies (f) at room temperature. At 10 kHz, the ρr has as large a value as 49, with ρ AC = 106 k Ω-cm and power loss 0.42. As f increases, all the three parameters are decreased monotonically to the values 28, 3.6 kΩ-cm, and 0.06 respectively. Almost a steady εr as well as ρAC value exists, with controlled power loss, useful for high frequency applications over f ≥ 400 kHz .

scholarly journals Effect of Transition Metal on Structural and Dielectric Properties of Mg0.5Tm0.5Fe2O4 (Tm = Zn and Cu) System

2021 ◽  
Author(s):  
Pallavi Saxena ◽  
Anand Yadav
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Interfacial Polarization ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
High Frequencies ◽  
X Ray ◽  
Cubic Structure ◽  
High Dielectric

This study explored the structural and dielectric features of Mg0.5Tm0.5Fe2O4 (Tm = Zn and Cu) that were synthesized by the Solid-state reaction (SSR) method. The X-ray powder diffraction (XRD) analysis reveals that the prepared samples are single-phase cubic structure without any impurity. Rietveld-refined X-ray diffraction results reveal the formation of cubic structure and all the peaks of Mg0.5Zn0.5Fe2O4 and Mg0.5Cu0.5Fe2O4 are perfectly indexed in the cubic (Fd-3 m) structure. Dielectric constant and dielectric loss variation with frequency were also explored. Both decrease when the relevant alternating field is increasing and become constant at high frequencies which reflects the important role of interfacial polarization. Furthermore, the Mg0.5Cu0.5Fe2O4 having the smallest crystallite size (~ 44.73 nm) has a high dielectric constant (~ 4.41 × 104) value as compare to Mg0.5Zn0.5Fe2O4.

scholarly journals Performance Analysis Of Electrical Properties Of Resin Transfer Molded Banana Leaf Reinforced Polymer Composites

2021 ◽  
Vol 23 (10) ◽  
pp. 179-194
Author(s):  
T. Rajamanikandan ◽  
◽  
Dr.S. Banumathi ◽  
Dr.R. Asokan ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Polymer Composites ◽  
Volume Resistivity ◽  
Dissipation Factor ◽  
Loading Frequency ◽  
Low Frequencies ◽  
High Frequencies ◽  
Reinforced Polymer ◽  
Fibre Loading ◽  
Banana Leaf

An investigation of the electrical characteristics of banana leaf reinforced Polymer composites made by resin transfer molding (RTM) has been carried out, with special emphasis on the effects of fibre loading, frequency and temperature. Every parameter, including the dielectric constant (ɛ0), dissipation factor (tan δ), loss factor (ɛ00), and conductivity, increases with increasing fibre concentration over the whole frequency range. A minimum fibre content of 50 % is required for composites to achieve excellent performance values. This increase is large at low frequencies, minimal at middle frequencies, and negligible at extremely high frequencies, according to the results of the study. At low frequencies, the volume resistivity fluctuates in response to fibre loading, while at high frequencies, the resistivity blends together. When the temperature rises, the dielectric constant values rise as well, however once the glass transition temperature is reached, the dielectric constant values fall. This fluctuates depending on the amount of fibre present. Finally, an attempt is made to establish a relationship between the experimental value of the dielectric constant and theoretical expectations.

scholarly journals Dielectric constants of solids at high frequencies and the influence of water of crystallization on dielectric constant

1937 ◽  
Vol 158 (893) ◽  
pp. 182-198 ◽  
Keyword(s):  
Dielectric Constant ◽  
Experimental Error ◽  
Dielectric Constants ◽  
The Other ◽  
High Frequencies ◽  
Influence Of Water

The determination of the dielectric constant of one constituent of a mixture, when the dielectric constants of the other component and the mixture itself are known, has been a problem which has been given much attention for many years. The familiar Clausius-Mossotti relationship for the dielectric constant of any substance is: ε-1/(ε + 2) d = A, where ε is the dielectric constant of the substance, d the density, and A a constant depending upon the polarizability of the molecule. This relation was developed independently by Clausius, Mossotti, Lorenz, Lorentz, Rayleigh, and Debye; but even in the case of pure liquids deviations well outside the experimental error have been found.

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