• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 13
  • 11
  • 5
  • 1
  • 1
  • Tagged with
  • 58
  • 33
  • 30
  • 27
  • 19
  • 10
  • 10
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A numerical model of the propagation characteristics of multi-layer ridged substrate integrated waveguide

Ainsworth, Joseph January 2012 (has links)
A transmission line format is presented which takes the form of a Multilayer Ridged Substrate Integrated Waveguide, for which signal energy is transmitted within standard PCB substrates, within a wave-guiding structure formed from conducting tracks in the horizontal plane and arrays of through-plated vias in the vertical plane. The Substrate Integrated Waveguide (SIW) is a recent development into which research is so far concentrated on single-layer rectangular variants which, like traditional rectangular waveguide, are amenable to analytic computation of the cutoff eigenvalues. Recent publications have offered empirically-derived relationships with which a Substrate Integrated Waveguide can be analysed by equivalence of the horizontal dimensions with a conventional waveguide, allowing such structures to be designed with minimal effort. We propose a ridged form of this structure, in which multiple PCB layers are stacked to obtain the desired height and the published equivalent width is used to obtain the horizontal dimensions. The proposed structure combines the increased bandwidth of ridged waveguide with SIW’s greatly reduced cost of manufacture and integration, relative to conventional waveguide, and improved power handling capacity and loss susceptibility relative to microstrip. Ridged variants have not yet been studied in the literature, however, in part because the eigenspectrum can not be obtained analytically. We thus present a semi-analytical software model with which to synthesise and analyse the cutoff spectrum in ridged Substrate Integrated Waveguide, verified by comparison with analytical solutions, where they exist, simulation in finite-element software and a physical prototype. Agreement with simulated and measured results is within 1 % in certain subsets of the parameter space and 11 % generally, and individual results are returned in times of the order of seconds. We use the model to analyse the relationship between geometry and frequency response, constructing an approximating function for the early modes which is significantly faster, such that think it can be used for first-pass optimisation. A range of optimal parameters are presented which maximise bandwidth within anticipated planar geometric constraints, and typical design scenarios are explored.
22

Enhanced fluid characterization in the millimeter-wave band using Gap Waveguide Technology

Arenas Buendia, Cristina 21 April 2016 (has links)
[EN] Microfluidic systems have been emerged as a promising technology for molecular analysis, biodefence and microelectronics. The properties of the microfluidic devices, such as rapid sample processing and the precise control of fluids, have made them attractive candidates to replace traditional experimental approaches. Microfluidic devices are characterized by fluidic channels with dimensions on the order of tens to hundreds of micrometers. Structures with this size enable the integration of lab-on-chip technology, which allows processing miniaturized devices for fluid control and manipulation. Fluid sensing by microwave sensors based on the RF analysis offers new possibilities for the characterization of mediums by non-invasive methods. Dielectric measurement of fluids is important because it can provide the electric or magnetic characteristics of the materials, which proved useful in many research and development fields, such as molecular biology and medical diagnosis. Several techniques are available in the frequency domain for analyzing the dielectric properties of liquids and their composition. We are focused in resonant cavity techniques for fluid characterization in the millimeter-wave range. However, these techniques are incompatible with lab-on-chip process due its dimensions in this frequency range. In this context, a new structure called gap waveguide appears as a good candidate to overcome the principal drawbacks of the classical resonant cavities. This thesis presents the development of the gap waveguide technology in the millimeter-wave band. Other conventional technologies are discussed as well, to compare them with the performance in terms of losses of the gap waveguide. We also present the resonator design based on gap waveguide with the purpose of making the gap waveguide a technology capable of working in the microfluidic sensing domain. In this context, we propose a comparative study between gap waveguide and Substrate Integrated Cavity (SIC) with the aim to characterize the fluid permittivity at 60 GHz. With this purpose, several prototypes have been manufactured with PCB ("Printed Circuit Board") and Low Temperature Co-fired Ceramic (LTCC) technologies. A work in the LTCC laboratory has been done with the purpose of validating some steps in the LTCC process which are key in the gap waveguide manufacturing, especially those related with the creation of cavities (external and internal) using LTCC materials. / [ES] Los sistemas microfluídicos han emergido como una tecnología prometedora para el análisis molecular, biodefensa y microelectrónica. Las propiedades de los dispositivos microfluídicos tales como el procesamiento rápido de las muestras y el control de los fluidos, les han hecho atractivos candidatos para reemplazar los tradicionales métodos experimentales. Los dispositivos microfluídcos están caracterizados por canales fluídicos con dimensiones del orden de decenas a centenares de micrómetros. Las estructuras con estos tamaños permiten la integración de la tecnología "lab-on-chip", la cual permite el procesamiento de dispositivos miniaturizados para el control y la manipulación de fluidos. La detección de fluidos a través de sensores de microondas basados en el análisis de radiofrecuencia ofrece nuevas posibilidades para la caracterización de medios a través de métodos no invasivos. Las medidas dieléctricas de los fluidos son importantes debido a que pueden proporcionar información las características eléctricas o magnéticas de los materiales, siendo útil en muchos campos de investigación y desarrollo tales como biología molecular o para realizar diagnósticos médicos. En el dominio frecuencial, varias tecnologías están disponibles en el mercado para analizar las propiedades dieléctricas y la composición de los líquidos. En esta tesis, estamos enfocados en las técnicas basadas en cavidades resonantes para la caracterización de fluidos en el rango de las ondas milimétricas. Sin embargo, estas técnicas son incompatibles con los procesos "lab-on-chip" debido a sus dimensiones en esta banda de frecuencia. En este contexto, una nueva estructura guía onda denominada "gap waveguide" aparece como un buen candidato para solventar los principales inconvenientes de las clásicas cavidades resonantes. En esta tesis se ha desarrollado la tecnología "gap waveguide" en la banda de ondas milimétricas. Otras tecnologías convencionales serán estudiadas para comparar el rendimiento de todas ellas en términos de pérdidas. También se presenta en esta tesis, el diseño de resonadores basados en la tecnología "gap waveguide" con el propósito de hacer esta tecnología compatible con la detección microfluídica. En este contexto, proponemos un estudio comparativo entre las tecnologías "gap waveguide" y "Substrate Integrated Cavity" (SIC) con el objetivo de caracterizar la permitividad de los fluidos a 60 GHz. Con este propósito, varios prototipos han sido fabricados usando las tecnologías PCB ("Printed Circuit Board") y LTCC ("Low Temperature Co-fired Ceramic". Un importante trabajo en el laboratorio LTCC se realizó para validar algunas de las etapas del proceso LTCC que eran la clave para la fabricación de prototipos basados en "gap waveguide", como la creación de cavidades (externas e internas) usando materiales LTCC. / [CAT] Els sistemes microfluídics han emergit com una tecnologia prometedora per a l'anàlisi molecular, biodefensa i microelectrònica. Les propietats dels dispositius microfluídics com el processament ràpid de les mostres i control dels fluids, els han fet atractius candidats per a reemplaçar les tradicionals aproximacions experimentals. Els dispositius microfluídcs estan caracteritzats per canals fluídics amb dimensions de l'orde de desenes a centenars de micròmetres. Les estructures amb estes grandàries permeten la integració de la tecnologia "lab-on-chip", la qual permet el processament de dispositius miniaturitzats per al control i la manipulació de fluids. La detecció de fluids a través de sensors de microones basats en l'anàlisi de radiofreqüència oferix noves possibilitats per a la caracterització de sistemes a través de mètodes no invasius. Les mesures dielèctriques dels fluids són importants pel fet que poden proporcionar informació sobre les característiques elèctriques o magnètiques dels materials, sent útil en molts camps d'investigació i desenvolupament com biologia molecular o per a realitzar diagnòstics. En el domini freqüencial, diverses tecnologies estan disponibles en el mercat per analitzar les propietats dielèctriques i la composició dels líquids. En aquesta tesi, estem enfocats en les tècniques basades en cavitats ressonants per a la caracterització de fluids en el rang de les ones mil·limètriques. No obstant això, aquestes tècniques són incompatibles amb els processos "lab-on-chip" a causa de les seues dimensions en aquesta banda de freqüència. En aquest context, una nova estructura guia onda denominada "gap waveguide" apareix com un bon candidat per a resoldre els principals inconvenients de les clàssiques cavitats ressonants. En aquesta tesi s'ha desenvolupat la tecnologia "gap waveguide" en la banda d'ones mil·limètriques. Altres tecnologies convencionals seran estudiades per a comparar el rendiment de totes elles en termes de pèrdues.També es presenta en esta tesi el disseny de ressonadors basats en la tecnologia "gap waveguide" amb el propòsit de fer esta tecnologia compatible amb la detecció microfluídica. En aquest context, proposem un estudi comparatiu entre les tecnologies "gap waveguide" i "Substrate Integrated Cavity" (SIC) amb l'objectiu de caracteritzar la permitivitat dels fluids a 60 GHz. Amb aquest propòsit, diversos prototips han sigut fabricats usant les tecnologies PCB ("Printed Circuit Board") i LTCC ("Low Temperature Co-fired Ceramic". Un important treball en el laboratori LTCC es va realitzar per a validar algunes de les etapes del procés LTCC que eren la clau per a la fabricació de prototips basats en "gap waveguide", com la creació de cavitats (externes i internes) usant materials LTCC. / Arenas Buendia, C. (2016). Enhanced fluid characterization in the millimeter-wave band using Gap Waveguide Technology [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62781 / TESIS
23

Analýza přechodů vedení v pásmech milimetrových vln / Analysis of planar junction in millimeter bands

Ambros, Martin January 2013 (has links)
This diploma thesis solves possibilities of transitions between waveguides and hybrid types of integrated microwave circuits. It describes the basic ways of solutions this transitions in both longitudinal and transverse as well. In thesis is also mentioned the principle of SIW technology, which is in this transitions widely used. The practical part is focused on the modeling and analysis of selected structures in CST MW Studio. Modeled structures are optimized for the lowest possible value insertion loss transition and are adapted to the characteristic impedance on 50. Selected structures are recalculated to a lower frequency band, realized and results of their simulation verified by measurements.
24

Solutions innovantes pour des filtres de fréquences volumiques et semi-volumiques performants, en céramique, silice fondue et thermoplastique COC/COP... : nouvelles alternatives pour les futurs programmes de satellite multimédia / Innovative solutions for efficient SIW & 3D frequency filters, on ceramic, fused silica and Cyclo Olefine COC/COP… : new alternatives for future multimedia Satellites programs

Abedrrabba, Sarra 11 December 2017 (has links)
L’émergence des satellites très haut débit pour la couverture des zones rurales s’accompagne de nombreuses contraintes technologiques. Dans le cadre du plan France très haut débit, le projet THD-sat proposé par le CNES se base sur l’utilisation des bandes Q et V pour assurer les liaisons avec les stations au sol et libérer de la ressource sur la bande Ka communément utilisée par les satellites ancienne génération. Avec la montée en fréquence, les besoins en termes de filtrage deviennent très stricts nécessitant des considérations particulières. Le premier chapitre reprend le contexte de l’étude et expose les différents éléments permettant de justifier le choix de la technologie SIW qui profite à la fois des bons facteurs de qualité des modes volumiques se propageant dans le substrat et de l’aisance du procédé technologique et de l’intégration des structures planaires. Les performances des cavités SIW restent néanmoins intimement liées à l’épaisseur de substrat qui doit être augmentée pour atteindre de meilleurs facteurs de qualité. L’augmentation de l’épaisseur de substrat s’accompagne de deux principales limitations : le rallongement des fils de « bonding » utilisés pour le câblage du filtre à son environnement MIC d’épaisseur 254 μm et l’élargissement de la ligne d’accès 50 Ω induisant des problèmes de discontinuités et d’excitations de modes parasites. L’approche suivie consiste à considérer des formes 3D permettant l’adaptation de mode et d’épaisseur entre une ligne microruban sur substrat de 254 μm d’épaisseur et le SIW d’épaisseur plus importante. Une nouvelle transition 3D est dès lors imaginée. Le chapitre II reprend les différents procédés technologiques utilisés pour la mise en forme et la métallisation des substrats 3D. Les substrats considérés sont l’alumine et la silice fondue mis en forme par ablation laser et le thermoplastique COP mis en forme par moulage. La principale limitation de l’ablation laser concerne les épaisseurs de substrat accessibles. Nous nous limitons à 635 μm dans le cas de l’alumine et à 500 μm dans le cas de la silice fondue. Le moulage polymère permet de s’affranchir de cette limitation et de viser des substrats plus épais (2 mm pour la solution COP).Le chapitre III reprend les étapes de conception des différentes solutions de filtrage avec la nouvelle transition 3D. Des résultats de mesures de différents prototypes réalisés sont par ailleurs présentés. Ces résultats sont globalement encourageants mais nécessitent d’être davantage développés pour être mieux exploitables. / The emergence of satellite high-speed internet for the coverage of rural zones is accompanied by numerous technological constraints. The current trend is to use higher frequency bands to release the satellite capacity for users. The increasing frequency requires new considerations especially for filtering needs which become notably strict in terms of performance and integration in small integrated circuits. This work introduces filtering solutions based on high quality factor Substrate Integrated Waveguides (SIW) using a novel 3D transition for a better integration in widely planar Hybrid ICs.The first chapter introduces the study’s context and the different elements justifying the use of the SIW technology.In fact, these structures profit from both the good quality factors of TE-modes propagating in the substrate and the easy fabrication process and integration of planar circuits. However, to increase the SIW quality factor, the substrate’s height should be increased which induces interconnection limitations such as long bond wires with high parasitic effects and large microstrip access lines with discontinuity problems and the propagation of parasitic modes. The adopted approach consists in imagining 3D shapes providing both mode and thickness matching between a microstrip line etched on a thin substrate and a high substrate SIW.The second chapter introduces the different manufacturing processes used for the substrate’s shaping and metallization. Three substrates are considered: Alumina, fused Silica and Cyclo Olefin Polymer COC. Alumina is widely used in space applications and has a well-mastered process. For equivalent dielectric losses, fused silica has a lower permittivity for bigger structures with less manufacturing tolerance sensitivity. Both Alumina and fused silica substrates are shaped using a laser ablation. The reachable substrate’s height using this machining method is relatively low. The polymer solution (COP) is elaborated using a molding process allowing higher substrates heights.The last chapter outlines the design steps of the different solutions and the measurement results of the first prototypes. These results are on the whole encouraging but require further development.
25

Antenas têxteis de micro-ondas. / Textile microwave antennas.

Marcus Grilo 09 December 2016 (has links)
Neste trabalho, foram desenvolvidas antenas têxteis de micro-ondas para aplicação em sistemas vestíveis, operando nas bandas ISM de 2,45 GHz e 5,8 GHz. Foram compiladas informações sobre o estado da arte em antenas têxteis, sendo realizado um estudo sobre antenas planares de micro-ondas e técnicas de alimentação das mesmas. Foi feita uma prospecção dos processos de fabricação de antenas têxteis de micro-ondas, definindo-se o processo e materiais têxteis usados na construção das antenas desenvolvidas. Procedeu-se à caracterização do tecido usado como substrato das antenas determinando-se suas características eletromagnéticas, utilizadas no projeto das antenas. Foram desenvolvidas antenas de microfita com plaqueta retangular e alimentação por sonda coaxial, para banda ISM de 2,45 GHz. Investigou-se o efeito da espessura do substrato da antena, tendo-se obtido experimentalmente larguras de banda de 4,8% e 6,0% para substratos com 0,7 mm e 1,4 mm de espessura, respectivamente. Foi proposta uma antena de microfita alimentada via acoplamento por proximidade que integra um transformador de um quarto de comprimento de onda ao circuito de alimentação, resultando em alargamento de banda da antena. Essa configuração foi utilizada no projeto de quatro antenas, que demonstraram experimentalmente larguras de banda de 11,2%, 13,4%, 17,0% e 24,0%. Uma configuração de antena têxtil empregando cavidade de um quarto de modo foi proposta para operação em banda dupla, sendo a tecnologia de guia de ondas integrado ao substrato - SIW, empregada em sua fabricação. Foi desenvolvido um procedimento de projeto para essa antena, o qual foi aplicado ao projeto de uma antena de banda dupla para as faixas ISM e 2,45 GHz e 5,8 GHz. Os resultados experimentais demostraram operação em banda dupla, com largura da banda inferior de 9,3%, e largura da banda superior de 9,2%. A antena de cavidade de quarto de modo apresentou as vantagens de maior ganho e menores dimensões relativamente às antenas têxteis de microfita desenvolvidas. De forma geral, os resultados experimentais dos protótipos construídos apresentaram boa concordância com os resultados fornecidos por simulação, demonstrando que as configurações de antenas propostas atenderam a seus objetivos, e a efetividade dos procedimentos de projeto adotado. / In this work, textile microwave antennas for use in wearable systems operating at 2.45 GHz and 5.8 GHz ISM bands were developed. Information on the state of art in textile antennas were compiled, and a study on microwave planar antennas and feeding techniques was performed. Processes for manufacturing textile microwave antennas were presented, and the fabrication process and textile materials used in this work were defined. The electromagnetic characteristics of the fabric used as antenna substrate were experimentally obtained, and used in the antenna design. Microstrip antennas using rectangular patch and coaxial probe feed were designed to operate at the 2.45 GHz ISM band. The effect of the antenna substrate thickness on the antenna characteristics was investigated, and experimental bandwidths of 4,8% and 6% were demonstrated for antennas with 0.7 mm and 1.4 mm thick substrates, respectively. A microstrip antenna fed by proximity coupling, including a quarter wavelength transformer at the feeding circuit, was proposed, resulting in the widening of the antenna bandwidth. This configuration was used to design four antennas, which experimentally demonstrated bandwidths of 11.2%, 13.4%, 17.0% and 24.0%. A textile antenna configuration employing a fourth mode cavity was proposed for dual band operation. Substrate integrated waveguide technology - SIW, was used for the antenna manufacturing. A design procedure was developed for this antenna, which has been applied to the design of a dual band antenna for the 2.45 GHz and 5.8 GHz ISM bands. The experimental results of this antenna demonstrated dual band operation, with 9.3% bandwidth at the lower band and 9.2% bandwidth at the higher band. The quarter mode cavity antenna presented the advantages of increased gain and smaller area than the designed textile microstrip antennas. In general, the experimental results of the fabricated prototypes exhibited good agreement with the results provided by simulation, demonstrating that the textile antenna configurations proposed met their expected performance and validating the design procedures adopted.
26

Antenas têxteis de micro-ondas. / Textile microwave antennas.

Grilo, Marcus 09 December 2016 (has links)
Neste trabalho, foram desenvolvidas antenas têxteis de micro-ondas para aplicação em sistemas vestíveis, operando nas bandas ISM de 2,45 GHz e 5,8 GHz. Foram compiladas informações sobre o estado da arte em antenas têxteis, sendo realizado um estudo sobre antenas planares de micro-ondas e técnicas de alimentação das mesmas. Foi feita uma prospecção dos processos de fabricação de antenas têxteis de micro-ondas, definindo-se o processo e materiais têxteis usados na construção das antenas desenvolvidas. Procedeu-se à caracterização do tecido usado como substrato das antenas determinando-se suas características eletromagnéticas, utilizadas no projeto das antenas. Foram desenvolvidas antenas de microfita com plaqueta retangular e alimentação por sonda coaxial, para banda ISM de 2,45 GHz. Investigou-se o efeito da espessura do substrato da antena, tendo-se obtido experimentalmente larguras de banda de 4,8% e 6,0% para substratos com 0,7 mm e 1,4 mm de espessura, respectivamente. Foi proposta uma antena de microfita alimentada via acoplamento por proximidade que integra um transformador de um quarto de comprimento de onda ao circuito de alimentação, resultando em alargamento de banda da antena. Essa configuração foi utilizada no projeto de quatro antenas, que demonstraram experimentalmente larguras de banda de 11,2%, 13,4%, 17,0% e 24,0%. Uma configuração de antena têxtil empregando cavidade de um quarto de modo foi proposta para operação em banda dupla, sendo a tecnologia de guia de ondas integrado ao substrato - SIW, empregada em sua fabricação. Foi desenvolvido um procedimento de projeto para essa antena, o qual foi aplicado ao projeto de uma antena de banda dupla para as faixas ISM e 2,45 GHz e 5,8 GHz. Os resultados experimentais demostraram operação em banda dupla, com largura da banda inferior de 9,3%, e largura da banda superior de 9,2%. A antena de cavidade de quarto de modo apresentou as vantagens de maior ganho e menores dimensões relativamente às antenas têxteis de microfita desenvolvidas. De forma geral, os resultados experimentais dos protótipos construídos apresentaram boa concordância com os resultados fornecidos por simulação, demonstrando que as configurações de antenas propostas atenderam a seus objetivos, e a efetividade dos procedimentos de projeto adotado. / In this work, textile microwave antennas for use in wearable systems operating at 2.45 GHz and 5.8 GHz ISM bands were developed. Information on the state of art in textile antennas were compiled, and a study on microwave planar antennas and feeding techniques was performed. Processes for manufacturing textile microwave antennas were presented, and the fabrication process and textile materials used in this work were defined. The electromagnetic characteristics of the fabric used as antenna substrate were experimentally obtained, and used in the antenna design. Microstrip antennas using rectangular patch and coaxial probe feed were designed to operate at the 2.45 GHz ISM band. The effect of the antenna substrate thickness on the antenna characteristics was investigated, and experimental bandwidths of 4,8% and 6% were demonstrated for antennas with 0.7 mm and 1.4 mm thick substrates, respectively. A microstrip antenna fed by proximity coupling, including a quarter wavelength transformer at the feeding circuit, was proposed, resulting in the widening of the antenna bandwidth. This configuration was used to design four antennas, which experimentally demonstrated bandwidths of 11.2%, 13.4%, 17.0% and 24.0%. A textile antenna configuration employing a fourth mode cavity was proposed for dual band operation. Substrate integrated waveguide technology - SIW, was used for the antenna manufacturing. A design procedure was developed for this antenna, which has been applied to the design of a dual band antenna for the 2.45 GHz and 5.8 GHz ISM bands. The experimental results of this antenna demonstrated dual band operation, with 9.3% bandwidth at the lower band and 9.2% bandwidth at the higher band. The quarter mode cavity antenna presented the advantages of increased gain and smaller area than the designed textile microstrip antennas. In general, the experimental results of the fabricated prototypes exhibited good agreement with the results provided by simulation, demonstrating that the textile antenna configurations proposed met their expected performance and validating the design procedures adopted.
27

Contribution à la modélisation des structures SIW et SINRD pour application micro-ondes et télécommunication / Contribution to the modeling of SIW and SINRD structures for microwave applications and telecommunications

Ismail Alhzzoury, Ahmad 25 June 2013 (has links)
Les développements technologiques en télécommunication et microondes tendent depuis plusieurs années vers la miniaturisation des circuits, une réduction des coûts, des masses et des pertes dans ces dispositifs. Les circuits SIW (Substrate Integrated Waveguide) s’inscrivent tout à fait dans cette mouvance et font à l’heure actuelle l’objet de nombreux sujets de recherche avec des applications directes dans l’industrie. Les circuits SINRD (Substrate Integrated Non Radiative Dielectric) utilisent eux les propriétés du substrat usiné (insertion de trous) pour la propagation du signal et des fonctions de l’électronique peuvent également être développées avec cette technologie. La conception de ces circuits passe généralement par des outils peu performants car non dédiés. Dans ce travail de thèse, une méthode numérique dédiée à ces circuits est développée. Elle est validée par comparaison à d’autres méthodes numériques et des mesures. Elle présente des temps de calcul très faibles. De nouveaux dispositifs pour des applications en télécommunications spatiales bas coûts et faibles pertes peuvent ainsi être développés grâce à elle. / For several years, technological developments in telecommunications and microwave circuit tend to miniaturization, low cost and mass reduction, in these devices. SIW Circuits (Substrate Integrated Waveguide) are developed in this manner and are currently the subject of numerous research topics with direct applications in industry. SINRD circuits (Substrate Integrated Non Radiative Dielectric) use micro machined substrate properties (insertion of holes) for signal propagation and electronic functions can be developed with this technology. The design of these circuits generally use unefficient tools that are not dedicated to these circuits. In this thesis, a numerical method dedicated to these circuits is developed. It is validated by comparison with other numerical methods and measurements. It presents very low computation time. New designs for applications in space communications and low-cost lowloss circuits may be developed through it.
28

Štěrbinová anténa pro pásmo X / Slot antenna for X band

Buriánek, František January 2013 (has links)
This work familiarizes readers with the issues of slot antennas. It presents design and simulation of slot antenna for X band in CST Microwave Studio program. The simulation procedure is described here, including all the settings required for proper operation of the simulation. Then there is the description of the principle of the Half-Mode Substrate Integrated Waveguide - HMSIW. In the end the designed structure of HMSIW and the slot antenna are assembled and measured. The results of the simulation are compared with the results acquired by measurements. The designed antenna at the frequency 10 GHz achieves the impedance bandwidth 255 MHz, and the gain 8,81 dBi (the simulated values in CST Microwave studio).
29

[pt] MODELAMENTO E CARACTERIZAÇÃO DE UMA ANTENA HOLOGRÁFICA DE IMPEDÂNCIA ARTIFICIAL OPERANDO NAS FREQUÊNCIAS DE MICROONDAS E TERAHERTZ / [en] MODELING AND CHARACTERIZATION OF A HOLOGRAPHIC ARTIFICIAL IMPEDANCE ANTENNA OPERATING IN MICROWAVE AND TERAHERTZ FREQUENCIES

YOIZ ELEDUVITH NUNEZ RUIZ 19 December 2019 (has links)
[pt] Este trabalho tem como objetivo apresentar o desenvolvimento de uma antena HAIA (Holographic Artificial Impedance Antenna) para potenciais aplicações em sistemas de satélites nas bandas X (8 - 12 GHz) e Ku (12 - 18 GHz), bem como na frequência de terahertz. Como prova de conceito, o protótipo é criado para operar na banda K (18 - 27 GHz), especificamente na frequência de 18,4 GHz. O HAIA é um tipo de antena com ondas vazadas, com um princípio operacional único para radiação de feixe controlado. Devido às suas amplas propriedades de radiação, o grau de liberdade do projeto nos permite explorar o comportamento de resposta da antena e diferentes parâmetros para sua modelagem são estudados. O projeto da antena obedece à teoria estabelecida para a radiação de ondas vazadas na conversão de uma onda de superfície para uma onda com vazamento, onde uma AIS (Artificial Impedance Surface) é caracterizada e distribuída em um substrato dielétrico usando o princípio holográfico desenvolvido no sistema óptico. A fim de minimizar as dimensões da antena, uma fonte planar é estudada para gerar uma onda de superfície e comparada com o desempenho da alimentação de onda de superfície convencional neste tipo de estrutura. Os diferentes projetos são avaliados para a conclusão do melhor resultado e comparados com outros trabalhos. O protótipo final é fabricado para testes experimentais, onde os resultados provam que a antena projetada responde às características modeladas, com uma boa concordância entre os resultados simulados e medidos. / [en] This work aims to present the development of a holographic artificial impedance antenna (HAIA) for potential applications in satellite systems in the X (8 - 12 GHz) and Ku (12 - 18 GHz) bands, as well as in the frequency of terahertz. As a proof of concept, the prototype is created to operate in the K (18 - 27 GHz) band, specifically at the design frequency of 18.4 GHz. HAIA is a kind of leaky-wave antenna (LWA) with a unique operating principle for controlled beam radiation. Due to their radiation characteristics are broad, and the degree of design freedom allows us to explore the antenna performance, different parameters are studied for modeling. The antenna design obeys the established theory for the leaky-wave radiation in the conversion of a surface wave into a leaky-wave, where an artificial impedance surface (AIS) is characterized and distributed on a dielectric substrate using the holographic principle developed in the optical system. In order to minimize the dimensions of the HAIA, a planar surface wave launcher is studied and compared with the performance of conventional surface wave feeding used in this type of structure. A series of designs are evaluated for the conclusion of the best result and compared with other works. The final prototype is manufactured for experimental tests, where the results show that the designed antenna responds to the modeled characteristics with a good agreement between the simulated and measured results.
30

Dielektrická rezonátorová anténa na bázi vlnovodu integrovaného do substrátu / Dielectric resonator antenna based on substrate integrated waveguide

Kubín, Petr January 2013 (has links)
The Master’s thesis deals with the design of the dielectric resonator antenna array based on the substrate integrated waveguide. The work describes various feed methods of the dielectric resonator antenna and the technique of the design of the antenna. The antenna array was designed in the simulative program ANSYS HFSS at the frequency 10 GHz, subsequently fabricated and measured. The antenna array has the bandwidth of 570 MHz for S11 better than –10 dB and the gain of 12.1 dBi.

Page generated in 0.411 seconds