Dielectric Properties of Glass Capillary Arrays

1998 ◽  
Vol 511 ◽  
Author(s):  
T. E. Huber ◽  
Leo Silber ◽  
Frank Boccuzzi
Keyword(s):  
Dielectric Constant ◽  
Effective Medium Theory ◽  
Far Infrared ◽  
Soda Lime ◽  
Index Of Refraction ◽  
Soda Lime Glass ◽  
Frequency Range ◽  
Glass Capillary ◽  
Medium Theory ◽  
X Band

ABSTRACTGlass Capillary Arrays (GCA) are low density columnar monolithic structures made of soda-lime glass. This structure, in which 76% of volume between the columns, the channels, is void, also has a greatly reduced dielectric constant in comparison with bulk glass. We have measured the index of refraction and absorption of samples of GCA's in the X-band, 8 × 109 Hz to 1.2×1010 Hz, for various orientations of the channels with respect to the polarization. For channels perpendicular to the polarization direction we have measured an index of refraction of 1.15. In comparison the index of refraction of (bulk) soda-lime glass is 2.6. We also examined the absorption in the far-infrared (FIR) frequency range between 6×1011 Hz and 6×1012 Hz. In this frequency range we obtain a k2 dependence due to losses in the glass matrix at higher frequencies. The results of the X-band and FIR results are interpreted in terms of an effective medium theory of the real and imaginary part of the dielectric constant of the composite.

Nanostructured Broad Band Infrared Absorber

2011 ◽  
Vol 1303 ◽  
Author(s):  
Timothy D. Corrigan ◽  
Dong Hun Park ◽  
Dennis Drew ◽  
Ray Phaneuf
Keyword(s):  
Effective Medium Theory ◽  
Scattered Light ◽  
Broad Band ◽  
Black Body ◽  
Index Of Refraction ◽  
Frequency Range ◽  
Multilayer Material ◽  
Medium Theory ◽  
Source Type ◽  
Broad Band Absorber

ABSTRACTWe describe a near perfect broad band absorber based on a laterally nanostructured multilayer material. We present calculations of the structure that demonstrates over 99% absorption of the 500 K black body spectrum. We also show the ability to manufacture an anti-reflective layer using a nanostructured metamaterial which allows us to tailor the index of refraction using effective medium theory. The absorber can be adapted for use in any frequency range and any source type. These materials may have applications in energy harvesting and scattered light control.

STUDY OF THE OPTICAL ABSORPTION OF Cu CLUSTERS IN THE Cu/ZnO SYSTEM

2001 ◽  
Vol 15 (17n19) ◽  
pp. 625-629 ◽  
Author(s):  
O. VAZQUEZ-CUCHILLO ◽  
A. BAUTISTA-HERNANDEZ ◽  
U. PAL ◽  
L. MEZA-MONTES
Keyword(s):  
Dielectric Constant ◽  
Optical Absorption ◽  
Free Path ◽  
Absorption Spectra ◽  
Effective Medium Theory ◽  
Composite Films ◽  
Mean Free Path ◽  
Optical Absorption Spectra ◽  
Medium Theory ◽  
Coated Nanoparticles

Optical absorption of Cu/ZnO composite films grown by r.f. sputtering are presented. We calculated the optical absorption spectra based on a colloidal-copper model with mean-free-path (MFP) and size corrections to the bulk dielectric constant. All effective-medium theory is used to analyze the presence of the coated nanoparticles and the ZnO matrix. The parameters of the model are fitted to reproduce the experimental spectra.

Effective Medium Theory of Dielectric Constant of Granular Materials in the Presence of Skin Effect

1990 ◽  
Vol 195 ◽  
Author(s):  
L.V. Panina ◽  
A.N. Lagar´kov ◽  
A. Ќ Sarychev ◽  
Y.R. Smychkovich ◽  
A.P. Vinogradov
Keyword(s):  
Dielectric Constant ◽  
Composite Material ◽  
Percolation Threshold ◽  
Granular Materials ◽  
Skin Effect ◽  
Effective Medium Theory ◽  
Critical Concentration ◽  
Medium Theory ◽  
Composite Systems ◽  
Conducting Component

We consider the behavior of the dielectric constant of percolation composite systems. An example of such systems is a composite material consisting of a disordered mixture of metallic and insulating particles. A reduction in concentration P of the metallic (conducting) component reduces the static conductivity of the composite, so that it vanishes at some critical concentration PC known as the percolation threshold.

Fan Shaped Patch with Fan Shaped Defected Ground Structure is designed for X-band Applications

2018 ◽  
Vol 8 (4) ◽  
pp. 57
Author(s):  
K.S. Ravi Kumar ◽  
Lalbabu Prasad ◽  
B. Ramesh ◽  
K.P. Vinay
Keyword(s):  
Dielectric Constant ◽  
Low Cost ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Frequency Range ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Band Region ◽  
X Band ◽  
Simulation Results

In this novel work a simple Fan Shaped Patch (FSP) Antenna is designed for X-band applications using Fan Shaped DGS structure to improve the Bandwidth and Gain. The Antenna is designed by using low cost FR4 Epoxy dielectric substrate material having dielectric constant of 4.4 with size 31.4x28.33x1.6mm3. The Antenna is simulated by using CST MW studio2014 software to analyze the results. The simulation results shows reasonable |S11|<-10 for the frequency range over 8.38 to 11.59GHz in X-band region.

Microstructural and Dielectric Responses of Calcium Copper Titanate Added Soda-Lime Glass for High Frequency Devices

2020 ◽  
Vol 1010 ◽  
pp. 233-238
Author(s):  
Mohd Fariz Ab Rahman ◽  
Mohd Fadzil Ain ◽  
Julie Juliewatty Mohamed ◽  
Siti Roshayu binti Hassan ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
High Frequency ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Glass Addition ◽  
Calcium Copper Titanate ◽  
High Frequency Devices ◽  
Xrd Patterns

The microstructures and dielectric responses of calcium copper titanate (CCTO) ceramics with soda-lime glass addition was investigated. The addition of soda lime glass was varied from 0-5 wt.% by solid-state reaction. The dielectric properties of CCTO indicated that dielectric constant was increased while dielectric loss was decreased after glass addition. The SEM micrographs showed the grain size of CCTO was decreased while the grain boundaries area of CuO + glass were increased after the addition of soda-lime glass. Both XRD patterns of CCTO and CCTO-soda lime glass sintered samples showed the formation of CCTO phase with minor peaks of CuO phase, respectively. These results indicated that soda-lime glass addition gave a significant effect on the microstructural and dielectric responses of CCTO ceramics.

On the microwave loss of granular high T c superconductors in the 0.1 GHz to 1 THz region

1991 ◽  
Vol 434 (1892) ◽  
pp. 555-570 ◽  
Keyword(s):  
Scattering Theory ◽  
Effective Medium Theory ◽  
Electromagnetic Coupling ◽  
Mie Scattering ◽  
Medium Theory ◽  
X Band ◽  
Metallic Inclusions ◽  
Microwave Loss ◽  
Microwave Applications ◽  
Mie Scattering Theory

The microwave loss of granular high T c superconductors in the 0.1 GHz to 1 THz region is studied, using an effective medium theory previously developed by us, that includes generalization of classical Mie scattering theory for spherical superconductor grains and an improvement due to electromagnetic coupling of the latter. As an illustration of the theory, we have made calculations for a typical granular YBa 2 Cu 3 O 7-δ material, in the low impurities fraction ( c p ) limit, for dielectric inclusions (voids) and normal metallic inclusions of the (non-superconducting) host material. Our results show that the loss for high quality granular thin films (HQTF) in this limit is independent of c P , except for an absolutely small value that is technologically unachievable. In view of the substrate losses and other considerations to be discussed, this suggests that the current HQTF performance is unlikely to be significantly superseded. Based on these findings, we confirm that for HQTF, the millimetre band ( ca . 100 GHz) and for bulk granular materials, the X band ( ca . 10 GHz), are likely to remain the highest frequency regions which are attractive for microwave applications, in accord with recent experiments.

scholarly journals Magnetic Field Effect of Near-Field Radiative Heat Transfer for SiC Nanowires/Plates

2018 ◽  
Vol 8 (11) ◽  
pp. 2023
Author(s):  
Zhiyuan Shen ◽  
Hao Wu ◽  
Han Wang
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Field Intensity ◽  
Effective Medium Theory ◽  
Near Field ◽  
Magnetic Field Effect ◽  
Medium Theory ◽  
Sic Nanowires ◽  
Magneto Optical Effect ◽  
Field Radiation

The SiC micro/nano-scale structure has advantages for enhancing nonreciprocal absorptance for photovoltaic use due to the magneto optical effect. In this work, we demonstrate the near-field radiative transfer between two aligned SiC nanowires/plates under different magnetic field intensities, in which Lorentz-Drude equations of the dielectric constant tensor are proposed to describe the dielectric constant as a magnetic field applied on the SiC structure. The magnetic field strength is qualified in this study. Using local effective medium theory and the fluctuation-dissipation theorem, we evaluate the near-field radiation between SiC nanowires with different filling ratios and gap distances under an external magnetic field. Compared to the near-field heat flux between two SiC plates, the one between SiC nanowires can be enhanced with magnetic field intensity, a high filling ratio, and a small gap distance. The electric field intensity is also presented for understanding light coupling, propagation, and absorption nature of SiC grating under variable incidence angles and magnetic field strengths. This relative study is useful for thermal radiative design in optical instruments.

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