Microwave Absorber Properties of Magnetic (Fe) and Dielectric (TiO2) Composite Materials for ETC in Free-Space

Radiation Absorbing Material (RAM) is used to absorb radiations of electromagnetic wave surrounding us. Thus, the multiple layers’ microwave absorber using biomass composite materials could be one of the solutions to address the problem. In order to effectively absorb the radiation of electromagnetic wave, the multiple layers’ absorber is characterized to optimize the performance of the absorber. The characterization is made by varying biomass composite material contents, thickness and other possible considerations. CST Microwave Studio software is first used to design and simulate the multiple layers’ absorber to estimate its performance. Development of multiple layers’ prototype is carried out to test its performance at free space environment. Free space dielectric measurement method is used to determine the value of multiple layers’ absorber dielectric. The dielectric value is then used in CST software in order to make the simulation more precise. Free space arch which is connected to Agilent Analyzer is used to measure absorption of multiple layers’ microwave absorber.

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Roll-to-Roll In-Line Implementation of Microwave Free-Space Non-Destructive Evaluation of Conductive Composite Thin Layer Materials

Applied Sciences ◽

10.3390/app11010378 ◽

2021 ◽

Vol 11 (1) ◽

pp. 378

Author(s):

Grigorios Koutsoukis ◽

Ivan Alic ◽

Antonios Vavouliotis ◽

Ferry Kienberger ◽

Kamel Haddadi

Keyword(s):

Thin Film ◽

Composite Materials ◽

Free Space ◽

Near Field ◽

Line Production ◽

Roll To Roll ◽

Corrugated Horn ◽

Evaluation Module ◽

Microwave Nondestructive Testing ◽

Non Destructive

A free-space microwave nondestructive testing and evaluation module is developed for the low-power, non-ionizing, contactless, and real-time characterization of doped composite thin-film materials in an industrial context. The instrumentation proposed is built up with a handled vector network analyzer interfaced with corrugated horn antennas to measure the near-field complex reflection S11 of planar prepreg composite materials in a roll-to-roll in-line production line. Dedicated modeling and calibrations routines are developed to extract the microwave conductivity from the measured microwave signal. Practical extraction of the radiofrequency (RF) conductivity of thin film prepreg composite materials doped with nano-powders is exemplary shown at the test frequency of 10 GHz.

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Ground and stratospheric flight tests on curing of composite materials in free space environment

10.26226/morressier.59c106e9d462b80292389e12 ◽

2017 ◽

Author(s):

Alexey Kondyurin

Keyword(s):

Composite Materials ◽

Free Space ◽

Space Environment ◽

Flight Tests

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A Study of Electromagnetic Absorption Performance of Modern Biomass Wall Tile

International Journal of Electrical and Electronic Engineering & Telecommunications ◽

10.18178/ijeetc.9.6.429-433 ◽

2020 ◽

pp. 429-433

Author(s):

Linda Mohd Kasim ◽

◽

Norhayati Mohamad Noor ◽

Hasnain Abdullah ◽

Azizah Ahmad ◽

...

Keyword(s):

Free Space ◽

Wall Tile ◽

Microwave Absorber ◽

Material Behavior ◽

Absorption Performance ◽

Biomass Materials ◽

Free Space Method ◽

Space Measurement ◽

Space Method ◽

Great Absorption

Electromagnetic elimination was used to eliminate unwanted radiation that may interface with machinery or affect human health. The use of microwave absorbers has become necessary for an environment with a safe electromagnetic wave level. The objectives of this project are to design a microwave absorber as a modern biomass wall tile and to investigate the absorbing performance of the modern wall tile absorbers with different materials. The absorber was designed with similar shapes and different biomass materials. The concept of modern wall tile had been applied to design the absorbers in terms of their shape and dimension by using biomass materials. Biomass materials such as kenaf and coconut coir were used in the study due to their lightweight and environmental-friendly material behavior. The simulation was done using CST Suite Studio software to predict the preliminary result of the absorbers. The proposed designs of the modern wall tile from the CST simulation are then fabricated while the mixtures of the materials are moulded into a microwave absorber. NRL Arch free space method was used to determine the absorption performance of the modern wall tile absorbers at a frequency range from 1GHz to 12GHz. Both results of the simulation and free space measurement are analyzed and discussed. This study showed that absorber KCA has the best performance among all the absorbers with the absorption of more than -10 dB. The mixture of biomass material with carbon has a great absorption performance compared to the mixture of biomass material without carbon.

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The use of carbon nanotubes to create materials that absorb electromagnetic radiation and electrodes of supercapacitors

Proceedings of the Voronezh State University of Engineering Technologies ◽

10.20914/2310-1202-2020-1-267-272 ◽

2020 ◽

Vol 82 (1) ◽

pp. 267-272

Author(s):

A. V. Shchegolkov ◽

F. F. Komarov ◽

I. D. Parafimovich ◽

O. O. Milchanin ◽

...

Keyword(s):

Carbon Nanotubes ◽

Composite Materials ◽

Free Space ◽

Carbon Nanostructures ◽

Electrode Materials ◽

Materials Science ◽

Acrylic Copolymer ◽

Current Densities ◽

Average Size ◽

20 Nm

Carbon nanotubes are effective nanomodifiers – providing the formation of a variety of thermal and electrophysical properties in composite materials. The functional purpose of composite materials determines the type and concentration of carbon nanostructures. The use of carbon nanostructures in polymer composites intended for electromagnetic shielding and electrode materials of supercapacitors is a promising direction in modern materials science. The method of manufacturing a radio-absorbing composite material included impregnation of a polyurethane foam billet – an aqueous composite suspension consisting of water, an acrylic copolymer, and carbon nanotubes "Taunit-MD". Structural studies of carbon nanotube samples were performed using transmission and scanning electron microscopy. To do this, PAM and SAM studies were performed using a HitachiH-800 electron microscope with an accelerating voltage of up to 200 Kev. For research purposes, electrodes with an area of 2 cm2 were made from carbon materials. Active mass was prepared from a carbon material and a binder, polivinildenftorid. Show PEM and SAM micrographs for samples of carbon nanotubes with the commercial name "Taunit-M". In this case, carbon nanotubes are characterized by smaller thicknesses in the range of 10-20 nm with a preferred average size of 12-15 nm. The structure of the tubes is very defective. The thickness of the tubes varies in some areas (not exceeding hundreds of nm) by more than 2 times. Carbon nanotubes have an irregular shape-there are processes, bends. The analysis of the obtained results allows us to conclude that the characteristic of the reflected EMI signal demonstrated by the pyramidal RPM is close in its values to that of the free space. At the same time, in comparison with the free space, there is a slight weakening (3-4) dB of the reflection coefficient. Carbon nanotubes MD has characteristics that exceed the carbon fabric "busofit" in terms of specific mass capacity, but inferior to it in terms of specific surface capacity. In addition, this advantage completely disappears at high current densities, which may be the result of a closed macrostructure and requires further optimization of the electrode manufacturing technology

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Creation of biological module for self-regulating ecological system by the way of polymerization of composite materials in free space

Advances in Space Research ◽

10.1016/j.asr.2004.01.019 ◽

2004 ◽

Vol 34 (7) ◽

pp. 1585-1591 ◽

Cited By ~ 7

Author(s):

A. Kondyurin ◽

B. Lauke ◽

I. Kondyurina ◽

E. Orba

Keyword(s):

Composite Materials ◽

Free Space ◽

Ecological System ◽

The Way

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Normal free space coupling of reflection-based fiber Bragg grating sensors embedded in composite materials

IEEE Photonic Society 24th Annual Meeting ◽

10.1109/pho.2011.6110753 ◽

2011 ◽

Author(s):

Liang Qiu ◽

Keith W. Goossen ◽

Dirk Heider ◽

Daniel J. O'Brien ◽

Eric D. Wetzel

Keyword(s):

Composite Materials ◽

Fiber Bragg Grating ◽

Free Space ◽

Bragg Grating ◽

Fiber Bragg Grating Sensors

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Tunable and Self-Sensing Microwave Composite Materials Incorporating Ferromagnetic Microwires

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.54.201 ◽

2008 ◽

Vol 54 ◽

pp. 201-210 ◽

Cited By ~ 27

Author(s):

Dmitriy Makhnovskiy ◽

Arkadi Zhukov ◽

V. Zhukova ◽

J. Gonzalez

Keyword(s):

Magnetic Field ◽

Composite Materials ◽

External Magnetic Field ◽

Resonance Frequency ◽

Free Space ◽

Effective Permittivity ◽

Stress Sensitivity ◽

Reflection And Transmission Coefficients ◽

Reflection And Transmission ◽

Transmission Coefficients

New types of stress sensitive and magnetic field tunable microwave composite materials are discussed where embedded short ferromagnetic microwire inclusions are used as controllable radiative elements. The dc external magnetic field is applied to the whole composite structure. And, the local stress is transferred to the individual microwires through the accommodating composite matrix. The spatial and angular distributions of microwires can be random, partly ordered, or completely ordered. For a wide frequency range, the free-space microwave response of a wire-filled composite can be characterized by a complex effective permittivity with resonance frequency dispersion. The latter depends on the conductive and magnetic properties of the microwire inclusions that contribute to the ac microwire magnetoimpedance (MI). In the vicinity of the so-called antenna resonance frequency, which is defined by the length of microwires and matrix dielectric constant, any variations in the MI of the microwires will result in large changes of the effective permittivity, and hence the reflection and transmission coefficients for an incident microwave. The field or stress dependence of the effective permittivity arises from the corresponding field or stress sensitivity of the MI in the ferromagnetic microwires with induced circumferential or helical magnetic anisotropy, respectively. The strong field tunable effect in the proposed composite materials can be utilized to introduce reconfigurable microwave properties in coatings, absorbers, and randomizers, and also in new media such as microwave metamaterials and bandgap wire structures. A maximum field tunability of 30 dB was achieved for free-space transmission measurements when the external magnetic field changed from zero to ~40 Oe. The stress sensitivity of reflection and transmission coefficients opens up new possibilities for the distant non-destructive testing and evaluation of composite materials both in the laboratory environment and large scale applications. The stress tunability of transmission coefficient may reach up to 5-8 dB within the elastic limit. The reflection coefficient usually demonstrates less tunability in both cases (field and stress dependent) and may require a multilayer structure to achieve better results, but it is always strong enough for the stress sensing applications.

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