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Design and fabrication of a novel wideband tem – cell for dielectric measurements

Dielectric properties measurement at microwave frequencies is required to illustrate how the electromagnetic waves propagate through the materials. Various methods have been used for the measurement of dielectric properties including both time and frequency domain methods. The existing systems ar...

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Main Author:	Yahya Sayegh, Ahmed Mohammed
Format:	Thesis
Language:	English English
Published:	2011
Subjects:	TK Electrical engineering. Electronics Nuclear engineering TK7800-8360 Electronics
Online Access:	http://eprints.uthm.edu.my/2588/1/24p%20AHMED%20MOHAMMED%20YAHYA%20SAYEGH.pdf http://eprints.uthm.edu.my/2588/2/AHMED%20MOHAMMED%20YAHYA%20SAYEGH%20WATERMARK.pdf http://eprints.uthm.edu.my/2588/
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spelling	my.uthm.eprints.25882021-11-01T02:48:32Z http://eprints.uthm.edu.my/2588/ Design and fabrication of a novel wideband tem – cell for dielectric measurements Yahya Sayegh, Ahmed Mohammed TK Electrical engineering. Electronics Nuclear engineering TK7800-8360 Electronics Dielectric properties measurement at microwave frequencies is required to illustrate how the electromagnetic waves propagate through the materials. Various methods have been used for the measurement of dielectric properties including both time and frequency domain methods. The existing systems are mainly based on coaxial probes, free space, and reflection/transmission method by using waveguide or coaxial cell and resonance techniques. Waveguide has the advantages of high power handling capability and low loss but it requires the sample to be machined out as fit as the cross section of the waveguide. Practically waveguides are not appropriate for lower frequencies due to the large size. Coaxial line technique has enough bandwidth but not easy to perform dielectric measurement for heavy and porous materials as concrete. It does not provide a uniform electromagnetic (EM) wave and the specimen needs to be in the shape of toroidal which is hard to achieve. In free space method a perfect normal plane wave is hard to achieve and as well as the diffraction effect of the sample edges cannot be avoided. In this project a novel wideband TEM cell in the frequency range from 50 MHz to 800 MHz based on parallel plate waveguide is presented suitable for transmission/reflection method. A specimen of dielectric material is put between the two parallel plates. The scattering parameters (S-parameters) of the two port line are measured using vector network analyzer. The Complex permittivity and permeability can be determined from the measured S-parameters using Nicolson-Ross-Weir (NRW) method. In order to validate the functionality of the parallel plate cell, the dielectric properties of Teflon is determined and shown. A good agreement among the experimental result, simulation result and the published values of the Teflon material is achieved. In addition to that the dielectric properties of concrete, wet and dry wood are investigated as well. Based on this agreement an original result of the dielectric properties of the concrete material is obtained and shown. 2011-12 Thesis NonPeerReviewed text en http://eprints.uthm.edu.my/2588/1/24p%20AHMED%20MOHAMMED%20YAHYA%20SAYEGH.pdf text en http://eprints.uthm.edu.my/2588/2/AHMED%20MOHAMMED%20YAHYA%20SAYEGH%20WATERMARK.pdf Yahya Sayegh, Ahmed Mohammed (2011) Design and fabrication of a novel wideband tem – cell for dielectric measurements. Masters thesis, Universiti Tun Hussein Malaysia.
institution	Universiti Tun Hussein Onn Malaysia
building	UTHM Library
collection	Institutional Repository
continent	Asia
country	Malaysia
content_provider	Universiti Tun Hussein Onn Malaysia
content_source	UTHM Institutional Repository
url_provider	http://eprints.uthm.edu.my/
language	English English
topic	TK Electrical engineering. Electronics Nuclear engineering TK7800-8360 Electronics
spellingShingle	TK Electrical engineering. Electronics Nuclear engineering TK7800-8360 Electronics Yahya Sayegh, Ahmed Mohammed Design and fabrication of a novel wideband tem – cell for dielectric measurements
description	Dielectric properties measurement at microwave frequencies is required to illustrate how the electromagnetic waves propagate through the materials. Various methods have been used for the measurement of dielectric properties including both time and frequency domain methods. The existing systems are mainly based on coaxial probes, free space, and reflection/transmission method by using waveguide or coaxial cell and resonance techniques. Waveguide has the advantages of high power handling capability and low loss but it requires the sample to be machined out as fit as the cross section of the waveguide. Practically waveguides are not appropriate for lower frequencies due to the large size. Coaxial line technique has enough bandwidth but not easy to perform dielectric measurement for heavy and porous materials as concrete. It does not provide a uniform electromagnetic (EM) wave and the specimen needs to be in the shape of toroidal which is hard to achieve. In free space method a perfect normal plane wave is hard to achieve and as well as the diffraction effect of the sample edges cannot be avoided. In this project a novel wideband TEM cell in the frequency range from 50 MHz to 800 MHz based on parallel plate waveguide is presented suitable for transmission/reflection method. A specimen of dielectric material is put between the two parallel plates. The scattering parameters (S-parameters) of the two port line are measured using vector network analyzer. The Complex permittivity and permeability can be determined from the measured S-parameters using Nicolson-Ross-Weir (NRW) method. In order to validate the functionality of the parallel plate cell, the dielectric properties of Teflon is determined and shown. A good agreement among the experimental result, simulation result and the published values of the Teflon material is achieved. In addition to that the dielectric properties of concrete, wet and dry wood are investigated as well. Based on this agreement an original result of the dielectric properties of the concrete material is obtained and shown.
format	Thesis
author	Yahya Sayegh, Ahmed Mohammed
author_facet	Yahya Sayegh, Ahmed Mohammed
author_sort	Yahya Sayegh, Ahmed Mohammed
title	Design and fabrication of a novel wideband tem – cell for dielectric measurements
title_short	Design and fabrication of a novel wideband tem – cell for dielectric measurements
title_full	Design and fabrication of a novel wideband tem – cell for dielectric measurements
title_fullStr	Design and fabrication of a novel wideband tem – cell for dielectric measurements
title_full_unstemmed	Design and fabrication of a novel wideband tem – cell for dielectric measurements
title_sort	design and fabrication of a novel wideband tem – cell for dielectric measurements
publishDate	2011
url	http://eprints.uthm.edu.my/2588/1/24p%20AHMED%20MOHAMMED%20YAHYA%20SAYEGH.pdf http://eprints.uthm.edu.my/2588/2/AHMED%20MOHAMMED%20YAHYA%20SAYEGH%20WATERMARK.pdf http://eprints.uthm.edu.my/2588/
_version_	1738581009917542400
score	13.211869

Design and fabrication of a novel wideband tem – cell for dielectric measurements

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