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SILVA, DENISE FREITAS. "APPLICATION METHOD OF MOMENTS FOR THE ANALYSIS OF CONICAL ANTENNAS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1999. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=7300@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORNeste estudo faz-se uma análise do desempenho de antenas cônicas compactas para operar em largas bandas de freqüência. Esta análise será feita observando o comportamento da impedância da antena. Serão, primeiramente, consideradas as estruturas convencionais formadas por cones e cones sobrepostos próximos a um plano condutor. Posteriormente, será considerada uma estrutura cônica onde o arredondamento das bordas resulta em um comportamento mais uniforme para a impedância de entrada com variações da freqüência, conferindo um aumento na banda para esta configuração.
The discone antenna is well known as an easy to build multioctave broadband antenna with a omnidirectional radiation pattern in the H-plane, It comprises a plane conductive disc element spaced close to and axially aligned with a conductive cone element. For applications in the UHF and microwave ranges, high performance antennas have been designed to operate from 0.5 to 5 GHz with a VSWR of about 3.5:1 or less. If the length is finite, the impedance still strongly dependent on apex angle as long as the cone is longer than about quarter of wavelength and the apex angle is relatively larger. A problem that is experienced with these antenna designs is the relatively large size required to operate at the low frequencies. In applications where utilization of this antenna. In this work, the analysis and design of these antenna is obtained by employing a rigorous formulation of the electromagnetic scattering problem. As a design tool, we employ Method of Moments for the analysis of rotationally symmetric structures excited by TEM mode. To properly account the variations in driven-point impedance with frequency, the coaxial waveguide used to feed the antenna is also included in the analysis. The excitation is simulated by a distribution of equivalent electric and magnetic currents placed inside the coaxial cable, over a cross-section plane. These currents are defined such that only excite the mode TEM towards the cable-antenna junction. These numerical tool is employed in the shaping the metallic surfaces involved in the discone-type antennas in order to obtain more compact structures. Simple solutions can be easily obtained making the center fed cone and the disc element with radially outer edge portions rolled backwardly and away from each other to form donut-shaped configurations. The ruled edges not only reduce the diameter of the antenna but also permit the current to flow around them smoothly and without reflections that degrade the VSWR at low end of the frequency band.
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Hertel, Thorsten Walter. "Analysis and design of conical spiral antennas in free space and over ground." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/15018.
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Liu, Xueli. "Origami Antennas for Novel Reconfigurable Communication Systems." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3644.
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Antennas play a crucial role in communication systems since they are the transmitting/receiving elements that transition information from guided transmission to open-space propagation. Antennas are used in many different applications such as aerospace communications, mobile phones, TVs and radios. Since the dimensions of antennas are usually physically proportional to the wavelength at their operating frequencies, it is important to develop large antennas and arrays that can be stowed compactly and easily deployed. Also, it is important to minimize the number of antennas on a platform by developing multifunctional antennas.
The first aim of this research is to develop new deployable, collapsible, light-weight and robust reconfigurable antennas based on origami principles. All designs will be validated through simulations and measurements. Paper as well as other substrates, such as, Kapton and fabric, will be used to develop our origami antennas. The second aim of this research is to derive integrated analytical and simulation models for designing optimal origami antennas for various applications, such as, satellite or ground communications.
This dissertation presents research on origami antennas for novel reconfigurable communication systems. New designs of reconfigurable monofilar, bifilar and quadrifilar antennas based on origami cylinders are developed and validated. Novel fabrication methods of origami antennas are presented with detailed geometrical analysis. Furthermore, multi-radii origami antennas are proposed, analyzed, fabricated and validated and they exhibit improved circular polarization performance and wide bandwidths. An actuation mechanism is designed for these antennas. For the first time, a low-cost and lightweight reconfigurable origami antenna with a reflector is developed here. In addition, an array is developed using this antenna as its element. Finally, a kresling conical spiral antenna and a spherical helical antenna are designed with mode reconfigurabilities.
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Khalil, Khaled. "Investigation, design and implementation of circular-polarised antennas for satellite mobile handset and wireless communications : simulation and measurement of microstrip patch and wire antennas for handheld satellite mobile handsets and investigations of polarization polarity, specific absorption rate, and antenna design optimization using genetic algorithms." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4319.
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The objectives of this research work are to investigate, design and implement circularly-polarized antennas to be used for handheld satellite mobile communication and wireless sensor networks. Several antennas such as Quadrifilar Spiral Antennas (QSAs), two arm Square Spiral and stripline or coaxially-fed microstrip patch antennas are developed and tested. These antennas are investigated and discussed to operate at L band (1.61-1.6214GHz) and ISM band (2.4835-2.5GHz) A substantial size reduction was achieved compared to conventional designs by introducing special modifications to the antenna geometries. Most of the antennas are designed to produce circularly-polarized broadside-beam except for wireless sensor network application a circularly-polarized conical-beam is considered. The polarization purity and Specific Absorption Rate (SAR) of two dual-band antennas for satellite-mobile handsets next to the human head are investigated and discussed, using a hybrid computational method. A small distance between the head and the handset is chosen to highlight the effects of the relatively high-radiated power proposed from this particular antenna. A Genetic Algorithm in cooperation with an electromagnetic simulator has been introduced to provide fast, accurate and reliable solutions for antenna design structures. Circularly-polarized quadrifilar helical antenna handset and two air-dielectric microstrip antennas were studied. The capabilities of GA are shown as an efficient optimisation tool for selecting globally optimal parameters to be used in simulations with an electromagnetic antenna design code, seeking convergence to designated specifications. The results in terms of the antenna size and radiation performance are addressed, and compared to measurements and previously published data.
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Cheng, Po-Kai. "NeXtRAD antenna design: X-Band dual polarised conical horn antenna." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20511.
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The purpose of the dissertation is to investigate a design and implementation of a dual polarised X-band antenna. The desired specifications include a centre frequency of 8.5 GHzand a 10_ azimuth-half power beam width in both vertical and horizontal polarisations. Other requirements include peak power handling of 400 W over a 50 MHz instantaneous bandwidth and the facility to be mounted on a standard tripod. The dissertation begins by introducing NeXtRAD, a radar project developed jointly by UCL and UCT, outlines the objective of the study and lists all the requirements to be achieved. After considering several types of antenna, horn antenna has been the most practical when trying to meet project requirements. Two of the horn antennas examined here have been the square and conical horn antennas using square and circular waveguides respectively. Each of these waveguides support dual polarisation as they provide a symmetrical structure in two orthogonal planes of polarisation. The square waveguide is flared into a square horn whereas the circular waveguide is flared into a conical horn to increase the gain and reduce the half-power beamwidth to the required angle.
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Douvalis, Vassileios. "Monolithic millimetre-submillimetre wave active conical horn antenna arrays." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414468.
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Mulenga, Charity Basaza. "The application of periodic structures to conical antenna design." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/33631.
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The primary objective of this research has been to investigate whether periodic structures can be applied to conical antennas for the purpose of improving their performance. This has been achieved through numerical modelling, theoretical investigation and physical measurements. In this study, two dimensional rotationally symmetric periodic structures were considered. This work determined that applying modifications to the cone antenna element significantly reduced the antennas bandwidth through the creation of strong anti-resonances. However, introducing frequency dependent impedance transformations to the end-termination leads to improvements in the far field radiation patterns without significant detriment to the input characteristics. In addition, periodic structures were applied to the ground plane to reduce backward radiation through the suppression of surface wave propagation. Results from this investigation have been determined and the implications assessed. In addition a novel periodic structure designed using polar curves and mapping functions capable of operating at low frequencies and that could be applied to conformal surfaces has been designed and analysed. The results of this research demonstrate that periodic structures can improve the radiation characteristics of conical antennas without compromising the impedance bandwidth.
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Clauzier, Sébastien. "Conception et réalisation d'antennes intégrables en mâture pour les plateformes navales : applications aux communications V/UHF et à un radar de navigation à balayage électronique en bande X." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S067.
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En raison des conflits maritimes qui s'étendent (piraterie, embargo,...), les besoins de communiquer et de détecter les menaces sont de plus en plus importants. Ceci conduit irrémédiablement à l'augmentation du nombre d'aériens à bord des plateformes navales. Afin de gérer au mieux cet accroissement du nombre d'antennes, qui conduit à des effets de couplage et à une augmentation de la signature radar du navire, les principales entreprises du secteur ont mis en place des structures de mâts intégrés. C'est dans un contexte d'amélioration de leur mâture intégrée compacte (Cmast™) que les Constructions Mécaniques de Normandie (CMN) de Cherbourg en collaboration avec l'IETR de Rennes et INEO Défense ont proposé cette thèse. Ces travaux ont pour objectifs le développement de deux systèmes antennaires intégrables au sein de cette mâture intégrée compacte : une antenne de communication en bande V/UHF et une antenne de radar de navigation à balayage électronique en bande X. Une première étude a permis le développement d'une antenne conique large bande (225-400MHz) dont les paramètres géométriques ont été optimisés pour assurer une communication entre les navires et des aéronefs. Un prototype de cette antenne a été réalisé et a permis une validation expérimentale de ses performances. Une seconde étude a permis le développement d'une antenne d'un radar de navigation à balayage électronique en bande X. Cette antenne est basée sur une technologie transmit-array comprenant une source illuminante et un réseau permettant la formation du diagramme. Un effort particulier a été porté sur la source illuminante qui doit éclairer, à des distances très courtes (<550mm), un réseau qui présente des dimensions particulières (1530mmx100mm). Plusieurs sources utilisant un principe de focalisation en zone champ proche ont été développées et validées expérimentalement. Enfin deux architectures d'antennes transmit-array ont été étudiées, utilisant respectivement une technologie imprimée et une technologie en guide. Le fonctionnement de l'antenne complète (source illuminante + réseau transmit-array) a été étudié théoriquementThe need to communicate and detect potential enemies increases with the extension of maritime conflicts. This need impacts directly the number of antennas on naval platforms. However, this increase of aerials leads to several damaging effects: like coupling or high radar signature. To limit this effect, some companies have developed integrated mast design. This structure limits the coupling effect between aerials by a subdivision of the mast and provides an omnidirectional coverage for all antennas inserted inside the mast. The objective of the thesis is to design two antenna systems for the compact integrated mast (CmastTM) developed by the Constructions Mécanique de Normandie (CMN): a communication antenna in the V/UHF band and an electronically scanning antenna for a maritime navigation radar in X-band. For the communication in the V/UHF band, a broadband conical antenna has been developed (225-400MHz). This antenna provides an optimized radiation pattern to insure the communications between the ship and the aircrafts. An experimental validation has been done with a prototype. In the second study, we have developed an electronically scanning antenna for a navigation radar. This antenna is based on a transmit-array technology including an illuminating feed and an antenna which generates the appropriate radiation pattern. A large part of the study has been done on the feed, which illuminates an array with specific dimensions (1530mmx100mm). Three different near-field focusing feeds have been developed and some of them have been validated experimentally. Then, two architectures of transmit-array antennas have been studied, using two different technologies: printed technology and a mixed technology with waveguide and horn
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Magnusson, Patrick. "Antenna for GNSS Reception in GEO-Orbit." Thesis, KTH, Rymd- och plasmafysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149283.
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There are a number of global navigation satellite systems (GNSS), in use or planed, which are used for navigation on earth but also for autonomous navigation of satellites in low earth orbit (LEO). It would be desirable to also have autonomous navigation in geosynchronous earth orbit (GEO) to reduce costs and make it possible to get higher accuracy on the position of the satellite. One part of the navigation system is the GNSS antenna which is examined in this master thesis. The specifications of the antenna were first decided and then three antenna alternatives were investigated in greater detail: a monofilar helix antenna, a three element circular array antenna and a twelve element circular array antenna. The result was that they would all work as a GNSS antenna in GEO but none could be judged to be the best under all circumstances. The size requirement for the mission and the used GNSS receiver would primarily decide which fits the mission best.Det finns ett antal världstäckande navigeringssystem (GNSS), i användning och planerade, som används för navigation på jorden fast också för autonom navigation för satelliter i låg bana runt jorden. Det skulle också vara önskvärt att använda autonom navigation för satelliter i geostationär omloppsbana (GEO) för att reducera kostnaden och få högre positions noggrannhet. En del av navigationssystemet är GNSS antennen vilken är undersökt i detta examensarbete. Specifikationerna för antennen bestämdes först och sedan undersöktes tre olika antennalternativ i detalj: en monofilär helixantenn, en tre elements cirkulär gruppantenn och en tolv elements cirkulär gruppantenn. Resultatet var att alla alternativen skulle fungera som en GNSS antenn i GEO-bana fast inget av alternativen är bäst i alla förhållanden. Storlekskraven för uppdraget och vilken GNSS mottagare som skall användas påverkar vilket av alternativen som passar uppdraget bäst.
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Descardeci, Jose Ricardo. "Antena de microfita sobre substrato conico." [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261183.
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Orientador : Attilio Jose GiarolaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: É apresentada neste trabalho a análise teórica de uma antena de microfita sobre um substrato cônico. A análise utiliza o modelo de cavidades com paredes laterais magnéticas na determinação da frequência de ressonância e impedância de a teoria das funções diádicas de Green, juntamente com as expressões assintóticas das funções esféricas de Hankel do segundo tipo, na obtenção dos campos distantes radiados pela antena. São apresentados também exemplos de antenas, operando no modo fundamental TM 01 e obtidos resultados para a frequencia de ressonância , impedância de entrada e diagrama de radiação do campo radiado distante. 0:1e resultados para a freqUência de ressonância, impedância de entrada e diagrama de radiação do campo radiado di stante. entrada da antena, e, juntamente com as esféricas de Hank el dist.antes radiados
Abstract: A theoretical analysis of a microstrip antenna on a conical substrate is presented. The cavity model with magnetic side walls is used for the calculation of the antenna resonant frequency and input impedance and the dyadic Green's functions formulation, in conjunction with asymptotic expressions of spher i cal Hank el functions of second type, are used for the calculation of the radiated fields in the far field region of the antenna. Some antennas, operating in the TM 01 mode were chosen as examples and numerical results for the resonant frequency, input impedance and radiation pattern were obtained.
Mestrado
Mestre em Engenharia Elétrica
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Conforti, Evandro 1947. "Antena a guia cilindrico-circular comterminação em flange conica." [s.n.], 1987. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261303.
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Tese (livre-docencia) - Universidade Estadual de Campinas, Faculdade de Engenharia EletricaMade available in DSpace on 2018-07-14T06:45:31Z (GMT). No. of bitstreams: 1 Conforti_Evandro_LD.pdf: 1411719 bytes, checksum: f7e679b0f5365ad3d77069e8c1581463 (MD5) Previous issue date: 1987
Resumo: Não informado
Abstract: Not informed
Tese (livre-docencia) - Univer
Livre-Docente em Engenharia Eletrica
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Lee, Kwan-Ho. "Polarization Characteristics of the Ultra Wide Band (UWB) Two Arm Conical Spiral Antenna." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392300599.
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Gehrki, Thomas D. "An analysis of the effects of feedline and ground screen noise currents on a conical monopole receiving antenna." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA283401.
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Všetula, Petr. "Kónický Sierpinského monopól." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218399.
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The thesis deals with numerical modeling of planar Sierpinski monopole and modified Sierpinski monopole, outgoing from Sierpinski structure. Next, it focuses on modeling of the conical modified monopole and conical Sierpinski monopole created by transferring of modified structure to conical surface. The properties of these multi-band antennas are verified by simulations in CST Microwave Studio 2009 and compared with the results published in available literature. The conical Sierpinski monopole is then optimized according to specified criteria. The optimized antenna is designed and its properties are experimentally verified.
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Smutný, Martin. "Anténa pro impulzní širokopásmový signál." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221227.
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The thesis describes retrievals of broadband antennas for VHF and UHF. It focuses on a compact antenna, potentially suitable for detecting electromagnetic impulses generated by electrical discharges in the dielectric oil in power transformers. This pulse signals are very steep with hundreds pico seconds rising edge. The thesis presents basic characteristics of antennas and selects those which have a major influence on the possibility of using the antenna in selected application. The appropriate antena is selected and proposal its geometrical parameters is discussed. The geometry of the selected antenna is designed for working bandwidth from about 200 MHz to about 1000 MHz. The newly designed double discon antenna is simulated and dimensions are optimized. Antenna is made and key characteristics of the antenna important for evaluate the ability of detecting the above-identified pulsed signals is measured. Antenna is compared with gain and characteristic of monocone antenna. Acquired knowledge and measured data are evaluated.
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PENCHEL, RAFAEL ABRANTES. "Synthesis of Offset Reflector Antennas Using Conic Sections and Confocal Quadric Surfaces." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=24631@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O presente trabalho propõe técnicas numéricas para a síntese de antenas refletoras que utilizando seções de cônicas ou superfícies quádricas confocais. Para tal, utilizando os princípios da Óptica Geométrica, foram desenvolvidos algoritmos capazes de sintetizar as superfícies refletoras desejadas. São analisadas duas geometrias distintas: a antena duplo-refletora com cobertura omnidirecional e a antena refletora offset com um único refletor. No primeiro problema, é apresentado um método alternativo para a síntese geométrica de antenas duplo-refletoras com cobertura omnidirecional e diagrama de radiação arbitrário no plano de elevação. O subrefletor é um corpo de revolução gerado por uma única seção cônica e o refletor principal modelado é gerado por uma série de seções cônicas locais sequencialmente concatenadas. Para ilustrar o método, duas configurações axialmente simétrica são sintetizadas para proporcionar diagramas de radiação uniforme ou cossecante ao quadrado no plano de elevação. Os resultados são validados por uma técnica híbrida baseada em Casamento de Modos e o Método de Momentos. No segundo problema, é investigado um procedimento numérico alternativo para a síntese geométrica de antenas refletoras offset com diagrama de radiação arbitrário na região de campo distante. O método usa superfícies quádricas confocais com eixos deslocados para representar localmente a superfície modelada. Nesta abordagem, um operador não linear deve ser resolvido como um problema de contorno. Para ilustrar o método, são apresentadas antenas modeladas para prover diagrama de radiação Gaussiano em contornos de cobertura circular, elíptico e super-elíptico.
This work proposes numerical techniques for synthesis of reflector antennas, using conic sections or confocal quadric surfaces. Under Geometrical Optics principles, algorithms to shape desired reflective surfaces have been developed. Two different geometries have been considered: omnidirectional dual-reflector antenna and single offset reflector antennas. In the first problem, it was presented an alternative method for synthesis of omnidirectional dual-reflector antennas with an arbitrary radiation pattern in elevation plane. The body-of-revolution subreflector is generated by a single conic section, while the shaped main reflector is generated by a series of local conic sections, sequentially consecutively concatenated. In order to illustrate the method, omnidirectional axisdisplaced ellipse (OADE) and Cassegrain (OADC) configurations are synthesized to provide uniform or cosecant squared radiation pattern in the elevation plane. The GO shaping results are validated by a hybrid technique based on Mode Matching and Method of Moments. In the second problem, an alternative numerical procedure was investigated for the geometrical synthesis of offset reflector antennas with an arbitrary radiation pattern in the far-field region, according to geometrical optics. The method uses local axis-displaced confocal quadric surfaces to describe the shaped reflector. In this approach, a nonlinear operator must be solved as a boundary value problem. To illustrate the method, we have chosen several offset configurations with circular, elliptical and super-elliptical contour coverage and Gaussian power density. The results were validated by the physical optics approximation.
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Levocký, Kristián. "Všesměrová anténa pro pásmo 60 GHz." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442415.
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This thesis deals with brief research on problematics of antennas in microwave band for omni-directional applications, own design and assembling of such an antenna. The purpose of the design is to have a best possible radiation patterns and reflection loss of our antenna. Conical monopole is chosen and it is simulated and changed to get the best possible parameters. Two prototypes are manufactured with mechanical changes applied and their parameters measured. Finished antenna is used for experimental channel measurement.
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Barbosa, Wagner Gomes. "Antena de microfita com um ou dois elementos radiadores, ressoando ao longo da Direção Azimutal, sobre Superficie Conica." [s.n.], 1995. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261205.
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Orientador: Attilio Jose GiarolaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Um desenvolvimento teórico é aqui apresentado para a análise de antenas de microfita sobre superfície cônica e operando no modo T MlO. Três antenas de microfita são propostas e analisadas, duas delas com um único patch e urna com dois patches, simetricamente localizados, ao redor da superfície cônica. Nessa análise, o modelo de cavidade com paredes laterais magnéticas é utilizado para o cálculo da freqüência de ressonância e da impedância de entrada. A formulação através das funções diádicas de Green é utilizada pa.ra a obtenção dos campos radiados pelas antenas, na região dos campos distantes. Resultados numéricos para essas antenas são apresentados para: 1) freqüência de ressonância, 2) impedância de entrada em função do ponto de alimentação e da freqüência e 3) diagrama de radiação. O conhecimento destes resultados é importante para o projeto das antenas consideradas
Abstract: A theoretical development is presented here for the analysis of microstrip antennas on a conical surface and operating in the T MIO mode. Three microstrip antennas are proposed and analyzed, two of them with a single patch and one with two patches, symmetrically located around the conical surface. In this analysis the cavity model with magnetic side walls is used for the calculation of the resonant frequency and input impedance. The dyadic Green's functions formulation is used for obtaining the fields radiated by the antennas, in the far field region. Numerical results for these antennas are shown for: 1) resonant frequency, 2) input impedance as function of feed position and of frequency, and 3) radiation pattern. The knowledge of these results is important for the design of this considered antennas
Mestrado
Mestre em Engenharia Elétrica
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Zheng, Yi. "Biological Agent Sensing Integrated Circuit (BASIC): A New Complementary Metal-oxide-semiconductor (CMOS) Magnetic Biosensor System." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/48892.
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Fast and accurate diagnosis is always in demand by modern medical professionals and in the area of national defense. At present, limitations of testing speed, sample conditions, and levels of precision exist under current technologies, which are usually slow and involve testing the specimen under laboratory conditions. Typically, these methods also involve several biochemical processing steps and subsequent detection of low energy luminescence or electrical changes, all of which reduce the speed of the test as well as limit the precision. In order to solve these problems and improve the sensing performance, this project proposes an innovative CMOS magnetic biological sensor system for rapidly testing the presence of potential pathogens and bioterrorism agents (zoonotic microorganisms) both in specimens and especially in the environment. The sensor uses an electromagnetic detection mechanism to measure changes in the number of microorganisms--tagged by iron nanoparticles--that are placed on the surface of an integrated circuit (IC) chip. Measured magnetic effects are transformed into electronic signals that count the number and type of organisms present. This biosensor introduces a novel design of a conical-shaped inductor, which achieves ultra-accuracy of sensing biological pathogens. The whole system is integrated on a single chip based on the fabrication process of IBM 180 nm (CMOS_IBM_7RF), which makes the sensor small-sized, portable, high speed, and low cost. The results of designing, simulating, and fabricating the sensor are reported in this dissertation.Ph. D.
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Lopez-Castellanos, Victor. "Ultrawideband Time Domain Radar for Time Reversal Applications." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1301040987.
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Zhu, F., Tahereh S. Ghazaany, Raed A. Abd-Alhameed, Steven M. R. Jones, James M. Noras, T. Suggett, and S. Marker. "Miniaturized tunable conical helix antenna." 2014. http://hdl.handle.net/10454/10833.
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NoA miniaturized conical helix antenna is presented, which displays vertical polarization with electrically small dimensions of 10mm×10mm×45mm. The resonance of the antenna is made tunable by adding a variable digital MEMS capacitor load at the bottom of the helix, giving a tuning range of 316 MHz to 400 MHz. The antenna demonstrates considerable impedance matching bandwidth and gain over the entire tuning frequency band. Most importantly, the antenna is capable of compact, flexible and easy integration into a wireless device package or for platform installation.
Datong of Seven Technology Group, for their support under the KTP project grant No. 008734.
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Lin, Shun-Yun, and 林淑芸. "NOVEL DESIGNS OF PATCH ANTENNAS WITH CONICAL RADIATION PATTERNS." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/76703338036414195311.
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Gardiner, John G., Raed A. Abd-Alhameed, Peter S. Excell, Neil J. McEwan, and Embarak M. Ibrahim. "A New Design of Horizontally Polarized and Dual-Polarized Uniplanar Conical Beam Antennas for HIPERLAN." 2003. http://hdl.handle.net/10454/2746.
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NoIt is shown that a conical beam 5.2-GHz antenna suitable for HIPERLAN application, but working in horizontal polarization, can be realized as a group of microstrip patch radiators in a ring formation. Layouts with three and four patches are described, and radiation patterns are found to agree well with predictions from a simple array model. The three-patch form is smaller and gives a closer approximation to an azimuth-independent pattern. Patterns are very similar to those achieved in vertical polarization with previously reported disk antenna realizations, giving peak radiation at about 50 elevation. Two methods of impedance matching are found to give satisfactory results. A dual-polarized conical-beam microstrip antenna, with a strictly uniplanar conductor pattern, is also presented and realized as an array of three square patches whose corners meet a central feed point. For the second polarization, the antenna functions as a series fed array. Fairly good conical beam patterns have been obtained, though only moderate polarization purity appears to be obtainable from threeelement arrays.
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Wu, Tsungyin. "Theoretical and experimental study of wide-band quasi-planar conical antennas." 2008. http://hdl.handle.net/10106/1098.
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"Gain and Loss Factor for Conical Horns, and Impact of Ground Plane Edge Diffractions on Radiation Patterns of Uncoated and Coated Circular Aperture Antennas." Doctoral diss., 2014. http://hdl.handle.net/2286/R.I.26819.
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abstract: Horn antennas have been used for over a hundred years. They have a wide variety of uses where they are a basic and popular microwave antenna for many practical applications, such as feed elements for communication reflector dishes on satellite or point-to-point relay antennas. They are also widely utilized as gain standards for calibration and gain measurement of other antennas.
The gain and loss factor of conical horns are revisited in this dissertation based on
spherical and quadratic aperture phase distributions. The gain is compared with published classical data in an attempt to confirm their validity and accuracy and to determine whether they were derived based on spherical or quadratic aperture phase distributions. In this work, it is demonstrated that the gain of a conical horn antenna obtained by using a spherical phase distribution is in close agreement with published classical data. Moreover, more accurate expressions for the loss factor, to account for amplitude and phase tapers over the horn aperture, are derived. New formulas for the design of optimum gain conical horns, based on the more accurate spherical aperture phase distribution, are derived.
To better understand the impact of edge diffractions on aperture antenna performance, an extensive investigation of the edge diffractions impact is undertaken in this dissertation for commercial aperture antennas. The impact of finite uncoated and coated PEC ground plane edge diffractions on the amplitude patterns in the principal planes of circular apertures is intensively examined. Similarly, aperture edge diffractions of aperture antennas without ground planes are examined. Computational results obtained by the analytical model are compared with experimental and HFSS-simulated results for all cases studied. In addition, the impact of the ground plane size, coating thickness, and relative permittivity of the dielectric layer on the radiation amplitude in the back region has been examined.
This investigation indicates that the edge diffractions do impact the main forward lobe pattern, especially in the E plane. Their most significant contribution appears in far side and back lobes. This work demonstrates that the finite edge contributors must be considered to obtain more accurate amplitude patterns of aperture antennas.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2014
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Τσομάκας, Δημήτριος. "Μελέτη και μοντελοποίηση της διάδοσης των ηλεκτρομαγνητικών κυμάτων σε γεωμετρίες που αντιστοιχούν σε πολικά συστήματα συντεταγμένων (κυλινδρικό, σφαιρικό)." Thesis, 2009. http://nemertes.lis.upatras.gr/jspui/handle/10889/1557.
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Το παρακάτω κείμενο αποτελεί διπλωματική εργασία που εκπονήθηκε στο Εργαστήριο Ασύρματης Επικοινωνίας του τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών του Πανεπιστημίου Πατρών. Σκοπός μας, ήταν η επίλυση των εξισώσεων του Maxwell σε προβλήματα που αφορούν το σφαιρικό και το κυλινδρικό σύστημα συντεταγμένων. Στην προσπάθεια αυτή κάναμε χρήση της μεθόδου επίλυσης των πεπερασμένων διαφορών στο πεδίο του χρόνου (F.D.T.D) σε δύο ειδών εφαρμογές: η πρώτη αφορά έναν κυλινδρικό κυματοδηγό, τον οποίο μοντελοποιήσαμε με τη βοήθεια του κυλινδρικού συστήματος συντεταγμένων και η δεύτερη αφορά μια κωνική κεραία UWB, την οποία μοντελοποιήσαμε με τη βοήθεια του σφαιρικού συστήματος συντεταγμένων. Η προσομοίωση αυτών των δύο εφαρμογών γίνεται με τη βοήθεια του προγραμματιστικού περιβάλλοντος της Matlab.
Επειδή η μέθοδος F.D.T.D επιλύει τις εξισώσεις του Maxwell στο χρόνο μας προσφέρει τη δυνατότητα της οπτικής απεικόνισης των πεδίων σε διάφορες χρονικές στιγμές, κάτι που μας επιτρέπει να παρατηρούμε τη χρονική εξέλιξη των φαινομένων. Η μέθοδος γίνεται ιδιαίτερα ελκυστική λόγω του επιπρόσθετου χαρακτηριστικού της απευθείας επίλυσης των εξισώσεων στροβιλισμού του Maxwell, καθιστώντας παράλληλα περιττή την επίλυση της κυματικής εξίσωσης.
Στο πρώτο κεφάλαιο γίνεται μια εισαγωγή στις υπολογιστικές τεχνικές στον ηλεκτρομαγνητισμό. Επίσης γίνεται μια πρώτη αναφορά στη μέθοδο των πεπερασμένων διαφορών στο πεδίο του χρόνου (F.D.T.D), στις δυνατότητες της μεθόδου, στο πεδίο εφαρμογής της καθώς και στα πλεονεκτήματά της.
Στο κεφάλαιο δύο παρουσιάζονται οι εξισώσεις του Maxwell. Συγκεκριμένα παρουσιάζονται οι εξισώσεις στροβιλισμού και οι βαθμωτές διαφορικές εξισώσεις που προκύπτουν από αυτές στις τρεις και δύο διαστάσεις. Στις δύο διαστάσεις γίνεται διάκριση σε εγκάρσιο ηλεκτρικό ρυθμό (Transverse Electric) και εγκάρσιο μαγνητικό ρυθμό (Transverse Magnetic). Τέλος παρουσιάζονται οι εξισώσεις του Maxwell που ισχύουν για τα σκεδαζόμενα πεδία.
Στο κεφάλαιο τρία παρουσιάζονται τα βασικά στοιχεία της μεθόδου F.D.T.D, τα οποία πρέπει να γίνουν κατανοητά προκειμένου να αναδειχθούν τα πλεονεκτήματα και τα μειονεκτήματά της. Συγκεκριμένα παρουσιάζονται οι εξισώσεις πεπερασμένων διαφορών, που προκύπτουν από τις βαθμωτές διαφορικές εξισώσεις, που προκύπτουν από τις εξισώσεις στροβιλισμού του Maxwell. Στη συνέχεια παρουσιάζονται βασικά χαρακτηριστικά της μεθόδου, όπως η επιλογή του χωρικού και χρονικού βήματος και η δημιουργία πηγών. Μετά παρουσιάζεται η σημαντικότερη απορροφητική οριακή συνθήκη PML του Berenger και τέλος οι υπολογιστικές απαιτήσεις του αλγορίθμου F.D.T.D.
Στο κεφάλαιο τέσσερα επιλύονται προβλήματα σε δύο διαστάσεις και συγκεκριμένα το πρόβλημα των ρυθμών διάδοσης TM και ΤΕ εντός κυλινδρικού κυματοδηγού με υλικό εντός του τον αέρα.
Στο κεφάλαιο πέντε επιλύονται προβλήματα σε δύο διαστάσεις. Συγκεκριμένα παρουσιάζει την ανάπτυξη ενός σετ εργαλείων λογισμικού που είναι χρήσιμα στην ανάλυση κεραιών και δομών εξαιρετικά ευρείας ζώνης (UWB). Αυτά τα εργαλεία χρησιμοποιούνται στην εκτέλεση προσομοίωσης με τη μέθοδο των πεπερασμένων διαφορών στο πεδίο του χρόνου (FDTD) μίας κωνικής κεραίας με συνεχές κύμα (CW) και παλμικές διεγέρσεις UWB. Η κεραία αναλύεται με τη χρήση εξισώσεων σφαιρικών συντεταγμένων FDTD που προέρχονται από τις βασικές αρχές. Τα αποτελέσματα της προσομοίωσης για τη διέγερση τύπου συνεχούς κύματος (CW) συγκρίνονται με τα αποτελέσματα από προσομοιώσεις και μετρήσεις σε δημοσιευμένες πηγές· τα αποτελέσματα της διέγερσης UWB είναι νέα.
Τα παραπάνω προβλήματα κάνουν σαφές το πόσο σημαντικό είναι να γνωρίζουμε σε βάθος τα χαρακτηριστικά της μεθόδου προκειμένου να φτάσουμε στην λύση τους. Σε περιπτώσεις όπου γνωρίζουμε τη λύση εκ των προτέρων (είτε ποιοτικά ή ποσοτικά) έχουμε τη δυνατότητα να επαληθεύσουμε την ορθότητα των αποτελεσμάτων της F.D.T.D. Οι λύσεις των προβλημάτων β
ασίζονται στην εύρεση των ολικών πεδίων. Ο εναλλακτικός τρόπος της εύρεσης των σκεδαζόμενων πεδίων δεν χρησιμοποιείται. Βέβαια στα προβλήματα ακτινοβολίας κεραιών υποχρεωτικά εφαρμόζεται η διατύπωση των ολικών πεδίων.
Μέσω αυτής της εργασίας έγινε σαφής η ικανότητα της F.D.T.D να εφαρμόζεται σε μεγάλη ποικιλία προβλημάτων. Κάτι που δεν έγινε σαφές είναι η δυνατότητα της μεθόδου να συνδυάζεται με άλλες μεθόδους, κάτι που μπορεί να επιφέρει σημαντική καταστολή ή και εξάλειψη των μειονεκτημάτων της. Με αυτό τον τρόπο δημιουργούνται νέες υβριδικές μέθοδοι. Με τις μεθόδους εύρεσης των ηλεκτρομαγνητικών πεδίων (όπως είναι η F.D.T.D) έχουμε τη δυνατότητα να δούμε τον ηλεκτρομαγνητισμό από νέα σκοπιά, κατανοώντας τον καλύτερα και προσαρμόζοντάς τον στις σύγχρονες ανάγκες της εποχής.-
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Dai, Yu-De, and 戴毓德. "Inverted Conical Plate Antenna for Wireless Application." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/e479f2.
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碩士國立彰化師範大學
電子工程學系
105
A new model of the antenna for wireless application is presented in this thesis. Inverted Conical Plate Antenna, which is the proposed antenna inspired by Conical Antenna. It can be used from bandwidth 2 GHz to 6 GHz. Moreover, the size of Inverted Conical Plate Antenna is relatively small compare to Conical Antenna but with high efficiency and high directionality. This thesis discusses both the design of Inverted Conical Plate Antenna and Conical Antenna. By doing experiments on changing the slots of Conical Antenna, I discovered the joint changing of current direction and current density and which lead to the characteristic of directional radiation. Two physical antennas are made with different slots and the data measured from physical antennas will also be compared with the simulated results on HFSS in this thesis.
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LAI, Yueh-Hung, and 賴岳宏. "Design and analysis of Broadband Conical EMP Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/23503775521813232481.
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碩士大葉大學
電信工程學系碩士在職專班
95
This research is focus on the design and the analysis of the broadband conical EMP (Electromagnetic Pulse) antenna, and the purpose is to use the antenna to be the EMP radiation structure of the high power unclear explosion. So that we can study the effect and the application of EMP in match with signal source of the high power in the future, to make sure that the information, the communication system and the flight vehicle of my country can still work well during the gradually developing electronic war even though use EMP of the high power interfere electromagnetic environment of the enemy. This research considers structure of the broadband conical EMP antenna, analyze pattern by general antenna types, and further use the FEM to analyze, and calculate the complicated antenna structure characteristics and the radiation pattern, and use the antenna performance to make the comparison and the improvement.
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Siao, Ming-Sheng, and 蕭名盛. "Multiband Planar Antenna Using Slots and A Novel Method of Radiation Characteristics Improvements for Conical Horn Antenna." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/66453619593507851454.
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碩士國立彰化師範大學
電信工程研究所
104
In this thesis, we propose two different types of antennas design. The first is the multiband planar antenna using slots and the second is a novel method of radiation characteristics improvements for conical horn antenna. The multiband planar antenna using slots is designed to be used for hotspots applications of 4G (LTE) and Wi-Fi. We use the asymmetrical conductor-backed finite-ground coplanar waveguide as the basic architecture and also acts as the main RF signal transmission path. The slots with different lengths and widths are placed in parallel with each other on the top and bottom ground planes to make multiple resonances at different frequencies, and therefore, to meet the broadband requirement. These slots are also used to control the current directions and thus, to determine a special characteristic mode that always radiate in the broadside direction for all working bands. In addition, the use the partial side wall, which act as a short path, can adjust the antenna input impedance and current directions for lower frequency band. Second, we consider the pyramidal horn antenna used as the primary feed of the reflector antenna of satellite communication systems. To meet the requirements of lower sidelobes, symmetrical and resemble radiation patterns for E-plane and H-plane, we propose a new method to improve the radiation characteristics of the feed horn. We arrange a metal cone in the central axis of the pyramidal horn antenna and the slope of this metal cone is nearly the same as that of the feed horn. The phase center point of the feed horn due to this inserted metal cone changes very little so that the relation distance between the reflector and this associated feed horn nearly the same. Finally, we will demonstrate our design methods and the measurement and simulation results are also discussed.
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"Antena de microfita com um ou dois elementos radiadores, ressoando ao longo da Direção Azimutal, sobre Superficie Conica." Tese, Biblioteca Digital da Unicamp, 1995. http://libdigi.unicamp.br/document/?code=vtls000085772.
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