scholarly journals Study of Stacked High Tc Superconducting Circular Disk Microstrip Antenna in Multilayered Substrate Containing Isotropic and/or Uniaxial Anisotropic Materials

2019 ◽  
Vol 8 (3) ◽  
pp. 1-5 ◽  
Author(s):  
A. S. Boughrara ◽  
S. Benkouda ◽  
A. Bouraiou ◽  
T. Fortaki
Keyword(s):  
Microstrip Antenna ◽  
Layer Structure ◽  
Fluid Model ◽  
Single Layer ◽  
Circular Disk ◽  
Complex Surface ◽  
Anisotropic Materials ◽  
High Tc ◽  
Two Fluid Model ◽  
Circular Disks

In this paper, we present a rigorous full-wave analysis able to estimate exactly the resonant characteristics of stacked high Tc superconducting circular disk microstrip antenna. The superconducting patches are assumed to be embedded in a multilayered substrate containing isotropic and/or uniaxial anisotropic materials (the analysis is valid for an arbitrary number of layers). London’s equations and the two-fluid model of Gorter and Casimir are used in the calculation of the complex surface impedance of the superconducting circular disks. Numerical results are presented for a single layer structure as well as for two stacked circular disks fabricated on a double-layered substrate.

scholarly journals Resonance of High Tc Superconducting Microstrip Patch in a Substrate-Superstrate Configuration

2014 ◽  
Vol 2 (3) ◽  
pp. 19 ◽  
Author(s):  
S. Benkouda ◽  
T. Fortaki ◽  
M. Amir ◽  
A. Benghalia
Keyword(s):  
Method Of Moments ◽  
Fluid Model ◽  
Complex Surface ◽  
Superconducting Thin Film ◽  
High Permittivity ◽  
High Tc ◽  
Microstrip Patch ◽  
Rectangular Patch ◽  
Two Fluid Model ◽  
Two Fluid

The effect of a protecting dielectric superstrate on the resonance of a high Tc superconducting microstrip patch is investigated. The analysis approach is based on the spectral-domain method of moments in conjunction with the complex resistive boundary condition. The complex surface impedance of the superconducting thin film is determined using London’s equation and the two-fluid model of Gorter and Casimir. Numerical results show that the resonant frequency of the high Tc superconducting rectangular patch decreases monotonically with increasing superstrate thickness, the decrease being greater for high permittivity loading.

scholarly journals Efficient CAD Model to Analysis of High Tc Superconducting Circular Microstrip Antenna on Anisotropic Substrates

2017 ◽  
Vol 6 (2) ◽  
pp. 40 ◽  
Author(s):  
S. Bedra ◽  
R. Bedra ◽  
S. Benkouda ◽  
T. Fortaki
Keyword(s):  
Fluid Model ◽  
Computational Cost ◽  
Extended Model ◽  
Cavity Model ◽  
High Tc ◽  
Anisotropic Substrates ◽  
Anisotropic Substrate ◽  
Two Fluid Model ◽  
Circular Microstrip Antenna ◽  
Low Computational Cost

In this paper, an electromagnetic approach based on cavity model in conjunction with electromagnetic knowledge was developed. The cavity model combined with London’s equations and the Gorter-Casimir two-fluid model has been improved to investigate the resonant characteristics of high Tc superconducting circular microstrip patch in the case where the patch is printed on uniaxially anisotropic substrate materials.  Merits of our extended model include low computational cost and mathematical simplify. The numerical simulation of this modeling shows excellent agreement with experimental results available in the literature. Finally, numerical results for the dielectric anisotropic substrates effects on the operating frequencies for the case of superconducting circular patch are also presented.

Electron and Phonon Thermal Conduction in Epitaxial High-Tc Superconducting Films

1993 ◽  
Vol 115 (1) ◽  
pp. 17-25 ◽  
Author(s):  
K. E. Goodson ◽  
M. I. Flik
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Size Effect ◽  
Free Path ◽  
Fluid Model ◽  
Mean Free Path ◽  
Boundary Scattering ◽  
High Tc ◽  
Two Fluid Model ◽  
Electron Mean Free Path

Electrons and phonons are the carriers of heat in the a-b plane of the high-Tc superconductor YBa2Cu3O7. In the absence of boundary scattering, the a-b plane thermal conductivity and the mean free path of each carrier type are calculated as functions of temperature using kinetic theory, the two-fluid model of the superconducting state, and experimental data for the thermal conductivity and electrical resistivity of a single crystal. The reduction by boundary scattering of the effective a-b plane thermal conductivity along an epitaxial YBa2Cu3O7 film is predicted as a function of temperature and film thickness. The size effect on the phonon conductivity dominates over the size effect on the electron conductivity. The predicted electron mean free path is limited by scattering on defects and is in very good agreement with experimental data from infrared spectroscopy.

scholarly journals Resonance of Superconducting Microstrip Antenna with Aperture in the Ground Plane

2013 ◽  
Vol 2 (2) ◽  
pp. 22
Author(s):  
S. Benkouda ◽  
T. Fortaki ◽  
M. Amir ◽  
A. Benghalia
Keyword(s):  
Microstrip Antenna ◽  
Ground Plane ◽  
Complex Surface ◽  
Published Data ◽  
Wave Analysis ◽  
High Tc ◽  
Microstrip Patch ◽  
Full Wave ◽  
Full Wave Analysis ◽  
Rectangular Microstrip Antenna

This paper presents a rigorous full-wave analysis of a high Tc superconducting rectangular microstrip antenna with a rectangular aperture in the ground plane. To include the effect of the superconductivity of the microstrip patch in the full-wave analysis, a complex surface impedance is considered. The proposed approach is validated by comparing the computed results with previously published data. Results showing the effect of the aperture on the resonance of the superconducting microstrip antenna are given.

scholarly journals Resonant Frequency and Bandwidth of Superconducting Microstrip Antenna Fed through a Slot Cut into the Ground Plane

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 147
Author(s):  
Ahmed Mahamdi ◽  
Siham Benkouda ◽  
Skander Aris ◽  
Tayeb A. Denidni
Keyword(s):  
Resonant Frequency ◽  
Microstrip Antenna ◽  
Fluid Model ◽  
Ground Plane ◽  
Rectangular Patch ◽  
Full Wave ◽  
Full Wave Analysis ◽  
Two Fluid Model ◽  
Half Power ◽  
Two Fluid

In this work, an efficient analysis is presented to accurately predict the resonant frequency and bandwidth of superconducting microstrip antenna fed through a slot cut into the ground plane. The effect of the superconductivity of the rectangular patch is introduced in the Full-wave analysis based on Gorter-Casimir two fluid model together with London brothers equations. In order to check the accuracy of the proposed approach, the obtained results have been compared with theoretical and experimental data reported in the literature. Finally, the influence of the slot on the resonant frequency and half-power bandwidth of the superconducting antenna has been investigated.

Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

2003 ◽  
Vol 125 (1) ◽  
pp. 103-109 ◽  
Author(s):  
C. Ramaswamy ◽  
Y. Joshi ◽  
W. Nakayama ◽  
W. B. Johnson
Keyword(s):  
Heat Dissipation ◽  
Layer Structure ◽  
Single Layer ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Small Range ◽  
Two Phase ◽  
Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

scholarly journals Natural modes of the two-fluid model of two-phase flow

2021 ◽  
Vol 33 (3) ◽  
pp. 033324
Author(s):  
Alejandro Clausse ◽  
Martín López de Bertodano
Keyword(s):  
Two Phase Flow ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Phase ◽  
Natural Modes ◽  
Two Fluid Model ◽  
Two Fluid

Self-consistent hydrodynamic two-fluid model of vortex plasma

2021 ◽  
Vol 33 (3) ◽  
pp. 037116
Author(s):  
Victor L. Mironov
Keyword(s):  
Fluid Model ◽  
Self Consistent ◽  
Two Fluid Model ◽  
Two Fluid
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