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study on the electromagnetic performance of body-worn radio units in the presence of scatterers in the proximity
Title
A study on the electromagnetic performance of body-worn radio units in the presence of scatterers in the proximity.
Creator
Peterson, Vance Howard, Florida Atlantic University, Ungvichian, Vichate, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The research addressed refers to a study on the electromagnetic performance aspects of body-worn radio units operating in the presence of scatterers in close proximity, using analytical, numerical, and experimental methods. The application potentials of such methods include evaluating the integrity of radio units such as cell phones. Consistent with the scope of the study above, considered in this research are specific details on analytical and numerical modeling of the effects of a nearby...
Show moreThe research addressed refers to a study on the electromagnetic performance aspects of body-worn radio units operating in the presence of scatterers in close proximity, using analytical, numerical, and experimental methods. The application potentials of such methods include evaluating the integrity of radio units such as cell phones. Consistent with the scope of the study above, considered in this research are specific details on analytical and numerical modeling of the effects of a nearby conducting cylindrical object on the electromagnetic field near a human-model phantom. Calculations are performed using the Finite Difference Time Domain (FDTD) method. Considered are various separations of the body wearing the test radio unit from the proximal object and polarization of the incident wave. An anechoic chamber and the test setup used for the measurement of EM field amplitudes near a saline-water phantom are described. Within the anechoic chamber, a small shielded loop is used as a field measurement probe and is positioned near the test phantom. The field probe orientation was in the vertical plane for characterizing the prevailing electromagnetic field intensity. This study indicates that variations in the field amplitude near the phantom occur, which are responsive to phantom rotation and measurement distance from the phantom. The electromagnetic field amplitude decreases rapidly with increasing distance between the probe and the surface of the phantom. The analysis is also extended to examine the electromagnetic field distribution in the gap between a human body phantom model and a nearby conducting cylinder. An appropriate three-dimensional FDTD method is presented and applied to a near-field problem of analyzing the influence of proximal conductive objects on fields near a phantom wearing an RF unit.
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Date Issued
2004
PURL
http://purl.flvc.org/fau/fd/FADT12085
Subject Headings
Scattering (Mathematics), Sound-waves (Scattering), Electromagnetic waves--Scattering, Electromagnetism--Computer simulation, Finite differences, Time-domain analysis
Format
Document (PDF)
Home Range and Habitat Use of Juvenile Green Turtlesin a Shallow Tidal Environment
Title
Plane-Wave Scattering of a Periodic Corrugated Cylinder.
Creator
Garcia, Samuel, Bagby, Jonathan Dr., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
In this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the...
Show moreIn this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the fields and boundary conditions used are discussed in detail. Axial and radial propagating modes for the scattered fields are derived and discussed. Close treatment is given to field equations summation truncation and conversion to matrix form, for numerical computing. A detailed account of the modeling approach using Mathematica® and NCAlgebra for the noncommutative algebra, involved in solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the scattered field of a periodic corrugated cylinder. The model is configured to approximate a smooth cylinder, which is then compared against that of a textbook standard smooth cylinder. The methodology and analysis applied in this research provide a solution for computational electromagnetics, RF communications, Radar systems and the like, for the design, development, and analysis of such systems. Through the rapid modeling techniques developed in this research, early knowledge discovery can be made allowing for better more effective decision making to be made early in the design and investigation process of an RF project.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004819
Subject Headings
Diffractive scattering., Radio frequency integrated circuits., Electromagnetic waves--Mathematical models., Electromagnetic waves--Diffraction., Electromagnetic waves--Scattering., Fourier transformations., Electromagnetic theory--Mathematical models.
Format
Document (PDF)
Plane-Wave Scattering of a Periodic Corrugated Cylinder
Title
Plane-Wave Scattering of a Periodic Corrugated Cylinder.
Creator
Garcia, Samuel, Bagby, Jonathan, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
In this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the...
Show moreIn this dissertation, a novel approach to modeling the scattered field of a periodic corrugated cylinder, from an oblique incident planewave, is presented. The approach utilizes radial waveguide approximations for fields within the corrugations, which are point matched to approximated scattered fields outside of the corrugation to solve for the expansion coefficients. The point matching is done with TMz and TEz modes simultaneously, allowing for hybrid modes to exist. The derivation of the fields and boundary conditions used are discussed in detail. Axial and radial propagating modes for the scattered fields are derived and discussed. Close treatment is given to field equations summation truncation and conversion to matrix form, for numerical computing. A detailed account of the modeling approach using Mathematica® and NCAlgebra for the noncommutative algebra, involved in solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the scattered field of a periodic corrugated cylinder. The model is configured to approximate a smooth cylinder, which is then compared against that of a textbook standard smooth cylinder. The methodology and analysis applied in this research provide a solution for computational electromagnetics, RF communications, Radar systems and the like, for the design, development, and analysis of such systems. Through the rapid modeling techniques developed in this research, early knowledge discovery can be made allowing for better more effective decision making to be made early in the design and investigation process of an RF project.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004819a
Subject Headings
Diffractive scattering., Radio frequency integrated circuits., Electromagnetic waves--Mathematical models., Electromagnetic waves--Diffraction., Electromagnetic waves--Scattering., Fourier transformations., Electromagnetic theory--Mathematical models.
Format
Document (PDF)
Influence of the boundaries on the acoustic scattering by a submerged target
Title
Influence of the boundaries on the acoustic scattering by a submerged target.
Creator
Charmes, Emmanuel., Florida Atlantic University, Beaujean, Pierre-Philippe, Cuschieri, Joseph M.
Abstract/Description
In shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free...
Show moreIn shallow water or fluid half-space, the acoustic scattering from a target is significantly different from that of an unbounded medium, due to the multiple reflections occurring between the target and the boundaries. The purpose of this thesis is to investigate the influence of the boundaries on the acoustic scattering of a rigid sphere by means of a superposition method. A minimum number of point sources necessary to accurately model the scattered field is determined in the case of a free medium, a fluid half-space and a waveguide. The free field symmetry vanishes due to the presence of boundaries and, at particular frequencies or scatterer depths, a significant change in the magnitude and spatial distribution of the scattered field occur. In an unbounded medium or fluid half space, the superposition method is shown to give similar results to analytical formulations found in the literature, provided enough point sources are used.
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Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/13211
Subject Headings
Electromagnetic waves--Scattering, Acoustical engineering, Sound-waves--Measurement, Wave-motion, Theory of
Format
Document (PDF)
Exploring the electromagnetics of millimeter-wave through terahertz spectrum: de novo studies vis-à-vis materials science, biomedical applications and wireless communication
Title
Exploring the electromagnetics of millimeter-wave through terahertz spectrum: de novo studies vis-à-vis materials science, biomedical applications and wireless communication.
Creator
Sharma, Bharti, Neelakanta, Perambur S., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics...
Show moreThe present research is a targeted endeavor to study the underlying characteristics and novel applications of millimeter (mm) wave through terahertz (THz) spectrum of electromagnetic (EM) energy. Focused thereof are the following specific tasks broadly considered pertinent to the said EM spectral range: (i) To elucidate the material characteristics vis-à-vis the interaction with EM energy at the test frequencies; (ii) to identify biomedical applications based on the material characteristics studied and applied to biomedia; and (iii) to model the wireless communication channels supporting EM waves at the test frequency bands of interest. Commensurate with the scope as above, the objectives of the research are as follows:
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004330, http://purl.flvc.org/fau/fd/FA00004330
Subject Headings
Electromagnetic waves -- Scattering, Pattern recognition systems, Scattering (Physics), Terahertz technology, Wireless communication systems
Format
Document (PDF)
Performance study of some diversity schemes in a Nakagami fading channel
Title
Performance study of some diversity schemes in a Nakagami fading channel.
Creator
Sannegowda, Ramesh Panditan., Florida Atlantic University, Aalo, Valentine A., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Closed form results for the symbol error probabilities are derived for M-ary, L branch Selection diversity schemes and Partial Decision combining schemes in a Nakagami fading environment using noncoherent frequency-shift keying modulation. The Maximum SNR selection, the Maximum output selection, the Optimal partial decision, and the Majority voting schemes are considered in this analysis. The analysis is not limited to integer values of the Nakagami fading parameter m. Results for the...
Show moreClosed form results for the symbol error probabilities are derived for M-ary, L branch Selection diversity schemes and Partial Decision combining schemes in a Nakagami fading environment using noncoherent frequency-shift keying modulation. The Maximum SNR selection, the Maximum output selection, the Optimal partial decision, and the Majority voting schemes are considered in this analysis. The analysis is not limited to integer values of the Nakagami fading parameter m. Results for the Rayleigh fading channel are obtained and presented as special cases of those of the Nakagami fading model. The symbol error probability when the diversity branches undergo different fading statistics with unequal mean SNR are considered for the Maximum SNR selection scheme. Outage probabilities are also calculated for some of the diversity combining schemes. A comparison of all the four schemes are discussed using the performance curves.
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Date Issued
1994
PURL
http://purl.flvc.org/fcla/dt/15011
Subject Headings
Electromagnetic waves--Transmission, Radio--Transmitters and transmission--Fading, Radio waves--Scattering
Format
Document (PDF)
Analysis and design of simulated human bodies using the finite difference time domain method
Title
Analysis and design of simulated human bodies using the finite difference time domain method.
Creator
Napoles, Adrian., Florida Atlantic University, Bagby, Jonathan S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
A three-dimensional finite difference time domain analysis of a saline water phantom used in industry for testing body-mounted receivers is presented. Specifically, a saline water phantom known as "Salty" is analyzed. Salty is an acrylic circular cylinder which is filled with a saline solution. The fields at the center of the cylinder and 1 cm external to the surface of the cylinder are obtained with the FDTD method for normally incident TMz and TEz plane wave excitation in free space. The...
Show moreA three-dimensional finite difference time domain analysis of a saline water phantom used in industry for testing body-mounted receivers is presented. Specifically, a saline water phantom known as "Salty" is analyzed. Salty is an acrylic circular cylinder which is filled with a saline solution. The fields at the center of the cylinder and 1 cm external to the surface of the cylinder are obtained with the FDTD method for normally incident TMz and TEz plane wave excitation in free space. The results from the FDTD simulation are then compared to the closed-form solution, which is obtained by assuming that Salty is infinitely long. A low dielectric constant simulated human body which emulates the performance of Salty is designed using the closed-form solution for the near fields of a two-layer cylinder and its performance is verified with the FDTD method.
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Date Issued
1995
PURL
http://purl.flvc.org/fcla/dt/15215
Subject Headings
Time-domain analysis, Beepers (Pagers), Electromagnetic waves--Scattering--Mathematical models
Format
Document (PDF)
Radiation and scattering of electromagnetic waves at the surfaces of composite materials: Surface immittance characterization via field compensation theorem
Title
Radiation and scattering of electromagnetic waves at the surfaces of composite materials: Surface immittance characterization via field compensation theorem.
Creator
Gu, Chaoli., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
This research addresses a specific class of electromagnetic problems concerning the radiation and scattering of high frequency electromagnetic waves at the surfaces of composite materials. With the advent of need-based developments in electromagnetic material technology, a research niche has stemmed to analyze the interaction of electromagnetic energy with different versions of composite materials used mostly as surface materials such as in radar-stealth applications. Mixture-dielectrics,...
Show moreThis research addresses a specific class of electromagnetic problems concerning the radiation and scattering of high frequency electromagnetic waves at the surfaces of composite materials. With the advent of need-based developments in electromagnetic material technology, a research niche has stemmed to analyze the interaction of electromagnetic energy with different versions of composite materials used mostly as surface materials such as in radar-stealth applications. Mixture-dielectrics, mixture magnetic materials, textured electromagnetic composites with matrix layers of lossy dielectric/magnetic materials, chiralic media, active surface materials etc. are a few emerging candidates of viable composites being considered in the state-of-the-art engineering electromagnetics. Specific to these materials, the analyses pertaining to electromagnetic radiation and scattering problems require a unique, approach vis-a-vis the heterogeneous properties of the composite material surfaces involved. Presently, the proximity of such surfaces is characterized and duly accounted for, by a mutual immittance formulation based on the Monteath's field compensation theorem. Using the relevant theoretical considerations, electromagnetic plane wave and/or focused beam radiation due to an aperture, conducting patch on flat and curved surfaces and scattering by an object coated with a composite material are elucidated. Also, an experimental method of evaluating the surface immittance is indicated. Theoretical computations are validated by comparing the results with those obtained via other methods. Some experimental results are furnished in support of the theoretical approaches presented.
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Date Issued
1993
PURL
http://purl.flvc.org/fcla/dt/12347
Subject Headings
Electromagnetic waves--Scattering, Composite materials, Radiation, Materials--Effect of radiation on
Format
Document (PDF)