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Electromagnetics and Photonics Commons™
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Articles 1 - 24 of 24
Full-Text Articles in Electromagnetics and Photonics
Archimedean Spiral Antenna Array With Klopfenstein And Exponential Tapered Balun Feeds, Leo Joseph Alvelais Iv, Paul Obrecht, Naguib Abdulla, Preston Mavady, Collin Fan
Archimedean Spiral Antenna Array With Klopfenstein And Exponential Tapered Balun Feeds, Leo Joseph Alvelais Iv, Paul Obrecht, Naguib Abdulla, Preston Mavady, Collin Fan
Electrical Engineering
This project presents the design, fabrication, and experimental evaluation of a broadband 3x3 Archimedean spiral antenna array tile for 2.8-3.8 GHz. Each element combines a two-arm spiral on Rogers RO4350B, a printed 50 to 150 Ω tapered balun, and a conductive backplane. Klopfenstein and Exponential feed implementations were modeled in Ansys HFSS, generated and tuned with automated scripting, fabricated, and evaluated with calibrated network and anechoic-chamber measurements. The Klopfenstein-fed hardware met the -10 dB input-reflection criterion across the project band. The exponential array provided a broad matched response but reached approximately -8 dB near 2.95 GHz. Measured center-element patterns retained …
Statistical And Spectral Theory For Spatially Correlated Random Aperiodic Antenna Arrays, Thomas Edward Christian Jr
Statistical And Spectral Theory For Spatially Correlated Random Aperiodic Antenna Arrays, Thomas Edward Christian Jr
Electrical and Computer Engineering ETDs
Aperiodic phased arrays enable beam steering, interference suppression, and spectrum efficiency for 6G, radar, biomedical imaging, and distributed sensing. Minimum inter-element spacing and keep out zones induce spatial correlation, violating the i.i.d. element-position assumption behind classical probabilistic random array theory. This dissertation develops a unified probabilistic spectral framework for correlated (non-i.i.d.) arrays. Second moment power pattern analysis incorporates the pair-correlation function and structure factor , recovering the i.i.d. limit when and accommodating unequal excitations. Side lobe and main lobe fields deviate from Rayleigh/Exponential and are modeled by weighted Nakagami and Gamma-mixture distributions, parameterized via Monte Carlo. The blue noise spectral …
Performance Of Siso And Mimo Antenna Systems In Suburban And Urban Scenarios For V2i Communications At 5.9 Ghz And 28 Ghz, Oluwaseun Falade
Performance Of Siso And Mimo Antenna Systems In Suburban And Urban Scenarios For V2i Communications At 5.9 Ghz And 28 Ghz, Oluwaseun Falade
Theses and Dissertations
As the need for Vehicle to Infrastructure (V2I) innovations increases, further research is needed to test the performance of antennas installed on vehicles in realistic scenarios including their radiation patterns and optimal location. This thesis considers realistic suburban and urban scenarios with SISO and MIMO antennas for V2I systems at 5.9 GHz and 28 GHz. The simulation is based on Ray tracing (RT) channel models to accurately model the effects of obstacles such as buildings and vehicles on the communication signals. Time-varying vehicular environments are simulated using a 3-D RT tool involving a vehicle and a base station. This research …
Adaptive Gps Antenna Array Beam Nulling Effectiveness Under Varying Antenna Element Positioning, Aadesh Neel
Adaptive Gps Antenna Array Beam Nulling Effectiveness Under Varying Antenna Element Positioning, Aadesh Neel
Electrical and Computer Engineering ETDs
Global Positioning System (GPS) is an essential part of modern life but is susceptible to same frequency jamming. GPS jamming can add excessive noise to a received low power signal and have the capability to change or completely distort information being sent through the GPS signal. Adaptive antenna arrays have long since been a solution to mitigating GPS jamming via beamnulling algorithms. However, there is little research on the effectiveness of these beamnulling algorithms under varying element positioning. In this work, an adaptive antenna array, consisting of Right-Hand Circularly Polarized (RHCP) nearly square GPS antenna elements, was constructed and tested …
The Electromagnetic Bayonet: Development Of A Scientific Computing Method For Aperture Antenna Optimization, Michael P. Ingold
The Electromagnetic Bayonet: Development Of A Scientific Computing Method For Aperture Antenna Optimization, Michael P. Ingold
Theses and Dissertations
The quiet zone of a radar range is the region over which a transmitted EM field approximates a uniform plane wave to within some finite error tolerance. Any target to be measured must physically fit within this quiet zone to prevent excess measurement error. Compact radar ranges offer significant operational advantages for performing RCS measurements but their quiet zone sizes are constrained by space limitations. In this work, a scientific computing approach is used to investigate whether equivalent-current transmitters can be designed that generate larger quiet zones than a conventional version at short range. A time-domain near-field solver, JefimenkoModels, was …
Pioneering Concepts For 3d Electromagnetics, Cesar Valle
Pioneering Concepts For 3d Electromagnetics, Cesar Valle
Open Access Theses & Dissertations
This work introduces two paradigm changing concepts that will push electromagnetics (EM) to the third dimension. The first of that work involves the introduction of the conformal Spatially Variant Lattice (SVL) algorithm that can conform any periodic structure onto arbitrary curvature. The algorithms robustness is confirmed by conforming a frequency selective surface (FSS) onto an extreme paraboloid, proving the algorithms robustness on high sloping surfaces. Three FSSs were made in total; a standard flat FSS, a projected FSS, and a FSS made through the conformal SVL algorithm. Measured results are shown and match well to simulation.Secondly, in the world of …
Advanced Manufacturing And Dielectric Material Characterization Techniques For High-Temperature Mm-Wave Antennas, Seng Loong Yu
Advanced Manufacturing And Dielectric Material Characterization Techniques For High-Temperature Mm-Wave Antennas, Seng Loong Yu
Doctoral Dissertations and Master's Theses
As traditional monitoring data sensors in high temperature environments such as gas turbine engines and aerospace applications are being replaced by wireless equivalents in recent years, there is a need for low-cost, low-time, and low-infrastructure alternatives to further push the state of the art. In this work, two aspects of high temperature materials in the above context are explored: (a) the development of advanced manufacturing techniques for high temperature materials that is lowcost, low-time, and low-infrastructure, and (b) the development of material characterization techniques that can be integrated with the manufacturing processes of high temperature materials. Additive manufacturing has been …
Magnetic Flux Channel Antenna Design In Conformal Applications, William J. Tremblay
Magnetic Flux Channel Antenna Design In Conformal Applications, William J. Tremblay
Theses and Dissertations
Magnetic Flux Channels (MFC) and Magneto-Dielectric Wire Antennas (MDWA) are effective, and in some cases, superior alternatives to traditional metallic antennas, in conformal and electrically small applications at the cost of fabrication and feed complexity. The frequency dispersive nature of magnetic material constituent parameters imposes constraints on the antenna design process, which were not fully developed in prior art. This research quantifies the key differences between the operating regions of magneto-dielectric materials for antenna applications and demonstrates the effectiveness of numerical method augmented modal analysis in the design process, regardless of operating region. Modeling challenges associated with MDWAs are addressed …
Analysis Of Miniaturized, Circularly Polarized Antennas For Bidirectional Propagation, Mason C. Moore
Analysis Of Miniaturized, Circularly Polarized Antennas For Bidirectional Propagation, Mason C. Moore
College of Graduate Studies: Theses & Dissertations
Size reduction is necessary to fit the recent demand for small sized communication systems in consumer electronics. Wireless communication systems rely on antennas for long range transmission of signals, so size reduced antennas have been sought after in recent years. Also, not many antennas are designed for use in bidirectional scenarios like subways, tunnels, bridges, etc. Three sized reduced antennas with circular polarization are presented for use in bidirectional communication systems. An electrically small pattern reconfigurable array, an electrically small two-sided printed cross dipole, and a size reduced printed wideband antenna are introduced within this thesis. All antennas’ results are …
A Brief Bibliometric Survey On Circularly Polarized Antennas For Mobile Communication, Aniket Gunjal, Abhaya Pal Singh
A Brief Bibliometric Survey On Circularly Polarized Antennas For Mobile Communication, Aniket Gunjal, Abhaya Pal Singh
Library Philosophy and Practice (e-journal)
This paper presents a database review on “Circularly Polarized Antennas for Mobile Communication” as it is the emerging technique used by mobile service provider because of having benefits over other types of antennas available.The polarization purity is now the major issue. In some cases due to cross polarization issue the antenna signal is cancelled at receiver side.So, it is necessary to have circularly polarized antenna to avoid this polarization issue because of change in phase of signal. The change in phase of signal is due to striking of wave on the obstacles and it slightly tilted from its direction causes …
Antennas For Wv Band Applications, Firas Ayoub
Antennas For Wv Band Applications, Firas Ayoub
Electrical and Computer Engineering ETDs
This dissertation focuses on designing, fabricating and testing antennas that are suitable for operation within the V/W bands. In particular, this work focuses on the design of slotted rectangular waveguide antenna arrays and cross slotted waveguide fed horn antennas. These structures are known for their high efficiency and high circularly polarized gain that can be implemented in satellite and terrestrial communication links. In addition, such designs can be implemented in radar applications that operate infrequency bands around 72 GHz or 84 GHz bands. Such antenna structures are inexpensive to fabricate since they can simply be machined using high precision conventional …
Novel Approaches For Mutual Coupling Reduction Among Vertical And Planar Monopole Elements, Ayman Abbosh Isaac
Novel Approaches For Mutual Coupling Reduction Among Vertical And Planar Monopole Elements, Ayman Abbosh Isaac
Theses and Dissertations
Modern wireless systems such as 4G LTE-A, RFID, Wi-Fi, WiMAX, and GPS utilize miniaturized antenna array elements to improve performance and reliability through diversity and increase throughput using spatial multiplexing schemes of MIMO systems. One original contribution in this thesis is to significantly reduce the complexity of traditional design approaches targeting mutual coupling reductions such as metamaterials, defected ground plane structures, soft electromagnetic surfaces using novel design alternatives. A decoupling network is proposed, which consists of a rectangular metallic ring along with two tuning strips printed on a dielectric substrate, surrounding a two-element monopole antenna array fed by a coplanar …
The Silver Lining: A Novel, Inkjet-Printed Mesh Coplanar-Slot Antenna For The Uhf Band, Anastasios C. Karles
The Silver Lining: A Novel, Inkjet-Printed Mesh Coplanar-Slot Antenna For The Uhf Band, Anastasios C. Karles
Undergraduate Research Posters
The Federal Communications Commission (FCC) is opening up frequencies within the television range (400MHz to 700MHz) of the Ultra High Frequency (UHF) band for use in emerging technologies, such as cognitive radio networks and machine-to-machine communication. In order for manufacturers to produce affordable antennas that can be used in these emerging technologies, inexpensive antennas are required that meet these new spectrum needs. This paper presents a mesh coplanar-slot bowtie patch antenna fabricated using commercially available inkjet-printing technology. Two antennas were fabricated: a 27x21cm copper FR4 antenna with .25mm lines and a 27x21cm silver antenna with 2mm lines fabricated using inkjet-printing. …
Engineered Nanocomposite Materials For Microwave/Millimeter-Wave Applications Of Fused Deposition Modeling, Juan De Dios Castro
Engineered Nanocomposite Materials For Microwave/Millimeter-Wave Applications Of Fused Deposition Modeling, Juan De Dios Castro
USF Tampa Graduate Theses and Dissertations
A variety of high-permittivity (high-k) and low-loss ceramic-thermoplastic composite materials as fused deposition modeling (FDM) feedstock, based on cyclo-olefin polymer (COP) embedded with sintered ceramic fillers, have been developed and investigated for direct digital manufacturing (DDM) of microwave components. The composites presented in this dissertation use a high-temperature sintering process up to 1500°C to further enhance the dielectric properties of the ceramic fillers. The electromagnetic (EM) properties of these newly developed FDM composites were characterized up to the Ku-band by using the cavity perturbation technique. Several models for prediction of the effective relative dielectric permittivity of composites based …
Miniaturized Wideband Planar Soft Surfaces For Mutual Coupling Reduction Between Antenna Elements, Said A. Abushamleh
Miniaturized Wideband Planar Soft Surfaces For Mutual Coupling Reduction Between Antenna Elements, Said A. Abushamleh
Theses and Dissertations
Miniaturized electromagnetic soft surfaces have promising applications in contemporary wideband portable wireless devices including, Multiple Input Multiple Output (MIMO) systems, dual frequency applications, and mutual coupling reduction among antennas in user terminals utilizing MIMO schemes such as in 4th generation Long-Term Evolution (4G-LTE). The use of textured metallic surfaces over grounded dielectric slab with vias for the suppression of electromagnetic wave propagation for applications including, but not limited to, mutual coupling reduction among closely-spaced antenna elements in antenna arrays, bandwidth enhancement, and gain enhancement has been extensively researched during the past two decades. In this dissertation, novel one-dimensional (1-D) periodic …
Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann
Contactless Measurement Of Angular Velocity Using Circularly Polarized Antennas, Vit Sipal, Adam Narbudowicz, Max Ammann
Articles
An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be easily adapted for both high and low angular velocity values. The precise alignment angle between the antennas can be determined if the initial antenna orientation is known. The angular error is shown to be
Reconfigurable Microstrip Antennas With Tunable Radiation Pattern Characteristics, Ahmed Khidre
Reconfigurable Microstrip Antennas With Tunable Radiation Pattern Characteristics, Ahmed Khidre
Electronic Theses and Dissertations
Reconfigurable beam antenna systems are capable of changing their radiation characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because of many reasons among them; it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand of wireless networks. It might also help to reduce the deployment cost of wireless networks infrastructures. In this dissertation, designs for reconfigurable beam microstrip antennas with tunable radiation characteristics have been proposed. The method to achieve these designs is the reconfigurable parasitic element …
Footwear Antennas For Body Area Telemetry, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Jacinta Browne, Louise Keating, Frances Horgan
Footwear Antennas For Body Area Telemetry, Domenico Gaetano, Patrick Mcevoy, Max Ammann, Jacinta Browne, Louise Keating, Frances Horgan
Articles
Antennas designed to link footwear sensors within body centric networks are introduced with two small UWB antennas, one directional and another quasi-omnidirectional. The radiating characteristics are evaluated for three positions on a sample sports shoe using a detailed simulation model and measurements with a homogenous foot phantom. Antenna performance is assessed for resilience to close proximity loading by the footwear materials and the phantom foot.
Novel Metamaterial Based Antennas For Flexible Wireless Systems, Haider Khaleel
Novel Metamaterial Based Antennas For Flexible Wireless Systems, Haider Khaleel
Theses and Dissertations
Recent years have witnessed a great deal of interest from both academia and industry in the field of flexible electronic systems. This research topic tops the pyramid of research priorities requested by many national research agencies. Consistently, flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today's information oriented society. On the other hand, metamaterials have become very popular in the design of contemporary antenna and microwave devices due to their wide range of applications derived from their unique properties which significantly enhances the performance of …
Novel Antennas Based On Innovations In Nano-Scale And Metamaterial Structures, Taha A. Elwi
Novel Antennas Based On Innovations In Nano-Scale And Metamaterial Structures, Taha A. Elwi
Theses and Dissertations
This dissertation focuses on the use of nano-scale and metamaterial structures for modern antenna applications including wearable devices, Global Positioning Systems, and self-powered wearable systems. Conductive composites, thin films, and array crystallography are nanostructural materials with superior properties that can be applied to printed electronic circuits, antennas, and optoelectronic devices. The feasibility of using conductive multi-walled carbon nanotube composites for printing patch antennas operating in the microwave range is demonstrated for the first time. A flexible meander sinusoidal patch based on a thin film of copper is presented for wearable medical telemetry devices. The effects of twisting and bending on …
Direction Finding With Mutually Orthogonal Antennas, David F. Chick
Direction Finding With Mutually Orthogonal Antennas, David F. Chick
Theses and Dissertations
Estimating the direction-of-arrival of incident electromagnetic plane waves (a.k.a. direction finding or DF) has typically been accomplished in the past using arrays of spatially separated antennas. The spatial separation produces a delay in each antenna's measured voltage due to the finite propagation time as the wave strikes each antenna in succession. In this thesis, we approach the problem differently by using three antennas that have been oriented in orthogonal directions but are co-located at the origin of a coordinate system. Being co-located, this mutually orthogonal arrangement of antennas cannot detect the propagation phase delay and must rely solely on the …
Standalone Antenna Demonstration System, Alexander James Hempy
Standalone Antenna Demonstration System, Alexander James Hempy
Master's Theses
Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill interest in the field of antenna design among high school and undergraduate college students. The system is portable, supplied solely by DC power supplies, easily reproducible, and includes rotational axes to illustrate antenna performance limitations and requirements. It provides a visual indication of wireless signal strength and demonstrates several antenna performance characteristics including polarization, gain and directivity, radiation patterns …
Novel Techniques For The Integration Of Antennas And Photovoltaic Cells, Maria Roo Ons, S. Shynu, Max Ammann, Sarah Mccormack, Brian Norton
Novel Techniques For The Integration Of Antennas And Photovoltaic Cells, Maria Roo Ons, S. Shynu, Max Ammann, Sarah Mccormack, Brian Norton
Conference Papers
Various novel approaches to the integration of antenna and photovoltaic technologies are proposed. These include the use of polycrystalline solar cells as groundplane for microstrip patch antennas as well as for reflectors of half-wave dipole antennas. Transparent materials were also evaluated as antenna radiating elements, allowing greater solar efficiency. A novel technique illustrating how emitter-wrap-through rear contact solar cells can be used as a folded-dipole antenna, which is located in the focal line of a parabolic solar concentrator, to provide high solar efficiency as well as high antenna gain, is presented.
Radar Cross Section Enhancement Of Simple Targets, Brian J. Crothers
Radar Cross Section Enhancement Of Simple Targets, Brian J. Crothers
Theses and Dissertations
This thesis explores the use of periodic open slots as passive antenna scatterers to enhance the radar cross section of a simple target. Two slot geometries are considered, thin rectangular slots and circular slots. Targets are modified with slot arrays of various element size, spacings, numbers, and geometries. These geometries were later backed by a cavity in an attempt to further enhance RCS. Measurements were taken and the results were compared to target baselines, which are nothing more than the unslotted version of the same target. Moment method solutions were also computed for comparisons with measured results. Additionally, an analytical …