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Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves./
作者:	Quan, Wei.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	198 p.
附註:	Source: Dissertations Abstracts International, Volume: 83-04, Section: B.
Contained By:	Dissertations Abstracts International83-04B.
標題:	Electrical engineering. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28716428
ISBN:	9798460464968

Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves.
Quan, Wei.

Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 198 p.

Source: Dissertations Abstracts International, Volume: 83-04, Section: B.

Thesis (Ph.D.)--Tufts University, 2021.

This item must not be sold to any third party vendors.

Precise microwave measurements of dielectric, and magnetic properties are performed in this thesis. The complex dielectric and magnetic resonance profiles are analyzed for discovery of material samples' properties and the application of resonance devices.The dielectric properties and ionic conductivity of novel "ceramic state" polymer electrolytes for high capacity lithium battery are characterized by Radio frequency and Microwave methods in broad frequency range from 4 GHz to 40 GHz. Such polymer exhibits properties more like a ceramic rather than polymer. In-waveguide measurement by vector network analyzer was applied to measure the complex dielectric spectra. The complex dielectric spectra are used to determine the complex alternating current electrical conductivity and thus the ionic conductivity.A novel 60 GHz Fabry-Perot open resonator system has been developed. The resonance cavity length of the system can be varied at ultra nano-scale step size to record the complete Gaussian profile for the determination of the dielectric permittivity and loss tangent of low loss solid materials with high precision. The vertical spatial tuning of the cavity length can be achieved as small as 10 nanometer steps to resolve ultra-fine spectral details of the fundamental resonance mode by specially designed micrometer and control system. It has been found that with the ultra nano-scale measurement technique the quality factor of the same Fabry-Perot resonator has increased by almost a factor of two experimentally. A comprehensive statistical study has also been carried out for identify sources of both random and systematic errors. The uncertainty of the real part of the permittivity of low loss solids can be achieved as small as 0.2% and 0.12% for the loss tangent measurement.RF resonant cavity thrusters are a new concept in propulsion that has the advantage of comparatively large thrust, simple structure and high reliability. Their workings are unknown, but since their reproduction by multiple independent laboratories they show evidence of a potential revolution in the physical sciences, but also require more systematic study of both the phenomenon and the various claims in the production of the device. An EMDrive system comprises a frustum microwave resonance cavity, microwave source, and load. The microwave beam generated by microwave source was input into the frustum microwave resonator to form a pure standing wave and electromagnetic pressure gradient. Thus, along the axial direction of the frustum microwave resonator, net thrust is formed. Current, unverified, theories related to EMDrive predict a net radiation pressure that scales with the Q factor (amount of reflections inside the cavity before the radiation is absorbed) of the cavity, which has been observed. This article, based on classical electromagnetic theory, introduce a building of a propellantless microwave propulsion system work at 2.45GHz. The measurement of Q-factor of this resonance cavity and relative analyze had been completed follow the EMDrive theory.Complex dielectric and magnetic properties of micro- and nano-size hexagonal ferrites have been studied in this thesis. Two different measurement techniques have been applied to characterize the samples in the broad frequency range from 1.7 GHz to 120 GHz. It was observed that the constitutive material properties, namely permittivity and permeability, as well as the ferromagnetic resonance frequency of the samples vary with the change in particle dimensions. Based on the results of these measurements, a model for calculating the ferromagnetic resonance frequency of ferrite powders has been derived, which takes into account the size and shape of the particles in the sample. It can be concluded from the size-dependent absorption properties observed in this study that these materials show promise as tunable millimeter wave absorbers.

ISBN: 9798460464968Subjects--Topical Terms:

649834
Electrical engineering.
Subjects--Index Terms:

Dielectric

Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves.
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245 1 0 $a Measurements of Dielectric and Magnetic Materials at Microwave and Millimeter Waves.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2021
300 $a 198 p.
500 $a Source: Dissertations Abstracts International, Volume: 83-04, Section: B.
500 $a Advisor: Afsar, Mohammed.
502 $a Thesis (Ph.D.)--Tufts University, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a Precise microwave measurements of dielectric, and magnetic properties are performed in this thesis. The complex dielectric and magnetic resonance profiles are analyzed for discovery of material samples' properties and the application of resonance devices.The dielectric properties and ionic conductivity of novel "ceramic state" polymer electrolytes for high capacity lithium battery are characterized by Radio frequency and Microwave methods in broad frequency range from 4 GHz to 40 GHz. Such polymer exhibits properties more like a ceramic rather than polymer. In-waveguide measurement by vector network analyzer was applied to measure the complex dielectric spectra. The complex dielectric spectra are used to determine the complex alternating current electrical conductivity and thus the ionic conductivity.A novel 60 GHz Fabry-Perot open resonator system has been developed. The resonance cavity length of the system can be varied at ultra nano-scale step size to record the complete Gaussian profile for the determination of the dielectric permittivity and loss tangent of low loss solid materials with high precision. The vertical spatial tuning of the cavity length can be achieved as small as 10 nanometer steps to resolve ultra-fine spectral details of the fundamental resonance mode by specially designed micrometer and control system. It has been found that with the ultra nano-scale measurement technique the quality factor of the same Fabry-Perot resonator has increased by almost a factor of two experimentally. A comprehensive statistical study has also been carried out for identify sources of both random and systematic errors. The uncertainty of the real part of the permittivity of low loss solids can be achieved as small as 0.2% and 0.12% for the loss tangent measurement.RF resonant cavity thrusters are a new concept in propulsion that has the advantage of comparatively large thrust, simple structure and high reliability. Their workings are unknown, but since their reproduction by multiple independent laboratories they show evidence of a potential revolution in the physical sciences, but also require more systematic study of both the phenomenon and the various claims in the production of the device. An EMDrive system comprises a frustum microwave resonance cavity, microwave source, and load. The microwave beam generated by microwave source was input into the frustum microwave resonator to form a pure standing wave and electromagnetic pressure gradient. Thus, along the axial direction of the frustum microwave resonator, net thrust is formed. Current, unverified, theories related to EMDrive predict a net radiation pressure that scales with the Q factor (amount of reflections inside the cavity before the radiation is absorbed) of the cavity, which has been observed. This article, based on classical electromagnetic theory, introduce a building of a propellantless microwave propulsion system work at 2.45GHz. The measurement of Q-factor of this resonance cavity and relative analyze had been completed follow the EMDrive theory.Complex dielectric and magnetic properties of micro- and nano-size hexagonal ferrites have been studied in this thesis. Two different measurement techniques have been applied to characterize the samples in the broad frequency range from 1.7 GHz to 120 GHz. It was observed that the constitutive material properties, namely permittivity and permeability, as well as the ferromagnetic resonance frequency of the samples vary with the change in particle dimensions. Based on the results of these measurements, a model for calculating the ferromagnetic resonance frequency of ferrite powders has been derived, which takes into account the size and shape of the particles in the sample. It can be concluded from the size-dependent absorption properties observed in this study that these materials show promise as tunable millimeter wave absorbers.
590 $a School code: 0234.
650 4 $a Electrical engineering. $3 649834
650 4 $a Applied physics. $3 3343996
653 $a Dielectric
653 $a Magnetic
653 $a Materials measurement
653 $a Microwave
653 $a Millimeter Waves
690 $a 0544
690 $a 0215
710 2 $a Tufts University. $b Electrical Engineering. $3 1030762
773 0 $t Dissertations Abstracts International $g 83-04B.
790 $a 0234
791 $a Ph.D.
792 $a 2021
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28716428