Eigenmodes of microwave cavities containing high-loss dielectric materials

2002 ◽  
Author(s):  
S.J. Cooke ◽  
B. Levush
Keyword(s):  
Dielectric Materials ◽  
High Loss ◽  
Microwave Cavities

Broadband terahertz metamaterial absorber enabled by using high-loss dielectric materials

2019 ◽  
Vol 6 (10) ◽  
pp. 105804
Author(s):  
Ben-Xin Wang ◽  
Chao Tang ◽  
Qingshan Niu ◽  
Yuanhao He ◽  
Huaxin Zhu ◽  
...  
Keyword(s):  
Dielectric Materials ◽  
Metamaterial Absorber ◽  
High Loss ◽  
Broadband Terahertz

scholarly journals Field Representation Microwave Thermography Utilizing Lossy Microwave Design Materials

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4830
Author(s):  
Christoph Baer ◽  
Kerstin Orend ◽  
Birk Hattenhorst ◽  
Thomas Musch
Keyword(s):  
Fluid Dynamics ◽  
Electromagnetic Fields ◽  
Dielectric Materials ◽  
Thermal Camera ◽  
Field Representation ◽  
High Loss ◽  
Electromagnetic Heating ◽  
X Band ◽  
Simple Estimation ◽  
Microwave Design

In this contribution, we are investigating a technique for the representation of electromagnetic fields by recording their thermal footprints on an indicator material using a thermal camera. Fundamentals regarding the interaction of electromagnetic heating, thermodynamics, and fluid dynamics are derived which allow for a precise design of the field illustration method. The synthesis and description of high-loss dielectric materials is discussed and a technique for a simple estimation of the broadband material’s imaginary permittivity part is introduced. Finally, exemplifying investigations, comparing simulations and measurements on the fundamental TE10-mode in an X-band waveguide are presented, which prove the above introduced sensing theory.

Microstructural characterization of YBaCuO Films on LaAlO3 substrates

1989 ◽  
Vol 47 ◽  
pp. 180-181
Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
N. Lewis ◽  
L. G. Turner
Keyword(s):  
Dielectric Constant ◽  
Single Crystal ◽  
Film Growth ◽  
Microstructural Characterization ◽  
Lattice Parameter ◽  
Film Plane ◽  
Substrate Material ◽  
High Loss ◽  
Amorphous Substrates ◽  
High Dielectric

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).

Evaluation of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings by the multi-frequency radio wave method of a slow surface electromagnetic waves

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin
Keyword(s):  
Radio Wave ◽  
Noise Level ◽  
Electromagnetic Waves ◽  
Dielectric Materials ◽  
Geometric Parameters ◽  
Experimental Investigations ◽  
Wave Method ◽  
Dielectric Coatings ◽  
Surface Electromagnetic Waves ◽  
Multilayer Dielectric

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.

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