No description available.

[pt] O termo de ondas milimétricas refere-se à porção do espectro eletromagnético com frequências entre 30 e 300 GHz, correspondente a comprimentos de onda de 10 até 1 mm. As características das ondas milimétricas diferem das microondas e das ondas infravermelhas, e são estas diferenças que fazem com que um sistema de ondas milimétricas seja o candidato ideal para algumas aplicações. Em anos passados a falta e o alto custo de fontes, dispositivos, componentes e instrumentação adequada para esta faixa de frequências, levaram a um progresso muito lento nesta área. Atualmente, com o planejamento da nova geração de comunicações móveis, isto está mudando e dispositivos nesta faixa de frequências estão sendo comercializados mundialmente. A faixa de operação pensada para a nova geração de comunicações móveis 5G vai de 24.25 GHz até 86 GHz. No Brasil, as faixas consideradas são de 24.25 GHz até 27.5 GHz e possivelmente de 37 GHz até 40 GHz. Neste trabalho vamos explorar a faixa de frequências entre 26.5 GHz e 40 GHz. Esta faixa já está sendo estudada por vários pesquisadores, porém ainda não existe muita literatura sobre resultados de medições em diferentes ambientes compostos por diferentes materiais. Neste trabalho serão apresentados resultados de medições de perda de penetração e coeficientes de reflexão em materiais de construção usuais. Também serão apresentados resultados de medições de perda de propagação em ambientes abertos (outdoor), realizadas no campus da PUC-Rio, e um modelo de predição desenvolvido com base nos resultados. Resultados de medições em ambientes fechados (indoor), realizadas no Centro de Estudos em Telecomunicações e num prédio da mesma universidade, também serão apresentados ao final desta tese. / [en] The millimeter wave term refers to the portion of the electromagnetic spectrum with frequencies between 30 and 300 GHz corresponding to wavelengths from 10 to 1 mm, that commercially is known as millimeter waves frequencies.The characteristics of millimeter waves differ from microwaves and infrared, and these differences make millimeter wave systems ideal candidates for some applications. In the past years, the lack and high cost of sources, devices, components and adequate instrumentation for this frequency range have caused a low progress. However, in the currently planning of the new generation of mobile communication system this is changing, and devices in this frequency range are being marketed worldwide. The frequency range proposed for new generation of mobile communication varies from 24.25 GHz to 86 GHz. In Brazil, the bands proposed are 24.25 GHz to 27.5 GHz and also from 27 GHz to 40 GHz. In this work, we will explore the range from 26.5 GHz to 40 GHz, due to equipment limitations. This frequency range is already being studied by several researchers. However, there is not extensive literature on measurement results in different environments or with different materials. This work will present results of penetration loss measurements in different materials, and the reflection coefficients for each material. Also, outdoor measurements made in the university campus will be presented and an improved path loss prediction method developed. Indoor measurements results, made in the Center of Studies in Telecommunications and in another building in the campus will also be presented.

Several propagation channel models are designed to verify signal behavior in specific environments for future 5G cellular networks. Hence, with the massive development and demand of indoor wireless systems, a suitable design prior to deployment is required for energy and cost-efficient implementations. These propagation channel models then should be designed to detect weak points in environments and enhance the accuracy of propagation channel modeling in any diverse indoor environment. This work presents the radio propagation analysis of millimeter waves using indoor model-based computational simulations of wireless coverage and material characterization at 28 GHz. Furthermore, the material characterization of common building materials is presented based on excess loss and penetration loss of the propagations in an indoor environment. To perform the analysis, a time static simulator in MATLAB with site-specific maps, deployments and an Indoor 3D propagation model are used to predict path loss in Line of Sight (LoS) and Non-Line of Sight (NLoS) conditions. / Flera spridnings kanal modeller är utformade för att verifiera signal beteende i specifika miljöer för framtida 5Gmobilnät. Med den massiva utvecklingen och efterfrågan på trådlösa inomhussystem krävs därför en lämplig design före driftsättning för energi och kostnadseffektiva implementeringar. Dessa spridnings kanal modeller bör sedan utformas för att upptäcka svaga punkter i miljöer och förbättra noggrannheten i föröknings kanal modellering i alla olika inomhusmiljöer. Detta arbete presenterar radio spridnings analysen av millimetervågor med hjälp av modellbaserade beräknings simuleringar inomhus av trådlös täckning och material karakterisering vid 28 GHz. Dessutom presenteras material karakteriseringen av vanliga byggmaterial baserat på överskottsförlust och penetrations förlust av förökningarna i en inomhusmiljö. För att utföra analysen används en statisk tids simulator i MATLAB med platsspecifika kartor, distributioner och en inomhus 3Dspridnings modell för att förutsäga banförlust i villkor för siktlinje (LoS) och icke-siktlinje (NLoS).

A new communication paradigm is foreseen for beyond 2020 society, due to the emergence of new broadband services and the Internet of Things era. The set of requirements imposed by these new applications is large and diverse, aiming to provide a ubiquitous broadband connectivity. Research community has been working in the last decade towards the definition of the 5G mobile wireless networks that will provide the proper mechanisms to reach these challenging requirements. In this framework, three key research directions have been identified for the improvement of capacity in 5G: the increase of the spectral efficiency by means of, for example, the use of massive MIMO technology, the use of larger amounts of spectrum by utilizing the millimeter wave band, and the network densification by deploying more base stations per unit area. This dissertation addresses densification as the main enabler for the broadband and massive connectivity required in future 5G networks. To this aim, this Thesis focuses on the study of the UDN. In particular, a set of technology enablers that can lead UDN to achieve their maximum efficiency and performance are investigated, namely, the use of higher frequency bands for the benefit of larger bandwidths, the use of massive MIMO with distributed antenna systems, and the use of distributed radio resource management techniques for the inter-cell interference coordination. Firstly, this Thesis analyzes whether there exists a fundamental performance limit related with densification in cellular networks. To this end, the UDN performance is evaluated by means of an analytical model consisting of a 1-dimensional network deployment with equally spaced BS. The inter-BS distance is decreased until reaching the limit of densification when this distance approaches 0. The achievable rates in networks with different inter-BS distances are analyzed for several levels of transmission power availability, and for various types of cooperation among cells. Moreover, UDN performance is studied in conjunction with the use of a massive number of antennas and larger amounts of spectrum. In particular, the performance of hybrid beamforming and precoding MIMO schemes are assessed in both indoor and outdoor scenarios with multiple cells and users, working in the mmW frequency band. On the one hand, beamforming schemes using the full-connected hybrid architecture are analyzed in BS with limited number of RF chains, identifying the strengths and weaknesses of these schemes in a dense-urban scenario. On the other hand, the performance of different indoor deployment strategies using HP in the mmW band is evaluated, focusing on the use of DAS. More specifically, a DHP suitable for DAS is proposed, comparing its performance with that of HP in other indoor deployment strategies. Lastly, the presence of practical limitations and hardware impairments in the use of hybrid architectures is also investigated. Finally, the investigation of UDN is completed with the study of their main limitation, which is the increasing inter-cell interference in the network. In order to tackle this problem, an eICIC scheduling algorithm based on resource partitioning techniques is proposed. Its performance is evaluated and compared to other scheduling algorithms under several degrees of network densification. After the completion of this study, the potential of UDN to reach the capacity requirements of 5G networks is confirmed. Nevertheless, without the use of larger portions of spectrum, a proper interference management and the use of a massive number of antennas, densification could turn into a serious problem for mobile operators. Performance evaluation results show large system capacity gains with the use of massive MIMO techniques in UDN, and even greater when the antennas are distributed. Furthermore, the application of ICIC techniques reveals that, besides the increase in system capacity, it brings significant energy savings to UDNs. / A partir del año 2020 se prevé que un nuevo paradigma de comunicación surja en la sociedad, debido a la aparición de nuevos servicios y la era del Internet de las cosas. El conjunto de requisitos impuesto por estas nuevas aplicaciones es muy amplio y diverso, y tiene como principal objetivo proporcionar conectividad de banda ancha y universal. En las últimas décadas, la comunidad científica ha estado trabajando en la definición de la 5G de redes móviles que brindará los mecanismos necesarios para garantizar estos requisitos. En este marco, se han identificado tres mecanismos clave para conseguir el necesario incremento de capacidad de la red: el aumento de la eficiencia espectral a través de, por ejemplo, el uso de tecnologías MIMO masivas, la utilización de mayores porciones del espectro en frecuencia y la densificación de la red mediante el despliegue de más estaciones base por área. Esta Tesis doctoral aborda la densificación como el principal mecanismo que permitirá la conectividad de banda ancha y universal requerida en la 5G, centrándose en el estudio de las Redes Ultra Densas o UDNs. En concreto, se analiza el conjunto de tecnologías habilitantes que pueden llevar a las UDNs a obtener su máxima eficiencia y prestaciones, incluyendo el uso de altas frecuencias para el aprovechamiento de mayores anchos de banda, la utilización de MIMO masivo con sistemas de antenas distribuidas y el uso de técnicas de reparto de recursos distribuidas para la coordinación de interferencias. En primer lugar, se analiza si existe un límite fundamental en la mejora de las prestaciones en relación a la densificación. Con este fin, las prestaciones de las UDNs se evalúan utilizando un modelo analítico de red unidimensional con BSs equiespaciadas, en el que la distancia entre BSs se disminuye hasta alcanzar el límite de densificación cuando ésta se aproxima a 0. Las tasas alcanzables en redes con distintas distancias entre BSs son analizadas, considerando distintos niveles de potencia disponible en la red y varios grados de cooperación entre celdas. Además, el comportamiento de las UDNs se estudia junto al uso masivo de antenas y la utilización de anchos de banda mayores. Más concretamente, las prestaciones de ciertas técnicas híbridas MIMO de precodificación y beamforming se examinan en la banda milimétrica. Por una parte, se analizan esquemas de beamforming en BSs con arquitectura híbrida en función de la disponibilidad de cadenas de radiofrecuencia en escenarios exteriores. Por otra parte, se evalúan las prestaciones de ciertos esquemas de precodificación híbrida en escenarios interiores, utilizando distintos despliegues y centrando la atención en los sistemas de antenas distribuidos o DAS. Además, se propone un algoritmo de precodificación híbrida específico para DAS, y se evalúan y comparan sus prestaciones con las de otros algoritmos de precodificación utilizados. Por último, se investiga el impacto en las prestaciones de ciertas limitaciones prácticas y deficiencias introducidas por el uso de dispositivos no ideales. Finalmente, el estudio de las UDNs se completa con el análisis de su principal limitación, el nivel creciente de interferencia en la red. Para ello, se propone un algoritmo de control de interferencias basado en la partición de recursos. Sus prestaciones son evaluadas y comparadas con las de otras técnicas de asignación de recursos. Tras este estudio, se puede afirmar que las UDNs tienen gran potencial para la consecución de los requisitos de la 5G. Sin embargo, sin el uso conjunto de mayores porciones del espectro, adecuadas técnicas de control de la interferencia y el uso masivo de antenas, las UDNs pueden convertirse en serios obstáculos para los operadores móviles. Los resultados de la evaluación de prestaciones de estas tecnologías confirman el gran aumento de la capacidad de las redes mediante el uso masivo de antenas y la introducción de mecanismos de I / A partir de l'any 2020 es preveu un nou paradigma de comunicació en la societat, degut a l'aparició de nous serveis i la era de la Internet de les coses. El conjunt de requeriments imposat per aquestes noves aplicacions és ampli i divers, i té com a principal objectiu proporcionar connectivitat universal i de banda ampla. En les últimes dècades, la comunitat científica ha estat treballant en la definició de la 5G, que proveirà els mecanismes necessaris per a garantir aquests exigents requeriments. En aquest marc, s'han identificat tres mecanismes claus per a aconseguir l'increment necessari en la capacitat: l'augment de l'eficiència espectral a través de, per exemple, l'ús de tecnologies MIMO massives, la utilització de majors porcions de l'espectre i la densificació mitjançant el desplegament de més estacions base per àrea. Aquesta Tesi aborda la densificació com a principal mecanisme que permetrà la connectivitat de banda ampla i universal requerida en la 5G, centrant-se en l' estudi de les xarxes ultra denses (UDNs). Concretament, el conjunt de tecnologies que poden dur a les UDNs a la seua màxima eficiència i prestacions és analitzat, incloent l'ús d'altes freqüències per a l'aprofitament de majors amplàries de banda, la utilització de MIMO massiu amb sistemes d'antenes distribuïdes i l'ús de tècniques distribuïdes de repartiment de recursos per a la coordinació de la interferència. En primer lloc, aquesta Tesi analitza si existeix un límit fonamental en les prestacions en relació a la densificació. Per això, les prestacions de les UDNs s'avaluen utilitzant un model analític unidimensional amb estacions base equidistants, en les quals la distància entre estacions base es redueix fins assolir el límit de densificació quan aquesta distància s'aproxima a 0. Les taxes assolibles en xarxes amb diferents distàncies entre estacions base s'analitzen considerant diferents nivells de potència i varis graus de cooperació entre cel·les. A més, el comportament de les UDNs s'estudia conjuntament amb l'ús massiu d'antenes i la utilització de majors amplàries de banda. Més concretament, les prestacions de certes tècniques híbrides MIMO de precodificació i beamforming s'examinen en la banda mil·limètrica. D'una banda, els esquemes de beamforming aplicats a estacions base amb arquitectures híbrides és analitzat amb disponibilitat limitada de cadenes de radiofreqüència a un escenari urbà dens. D'altra banda, s'avaluen les prestacions de certs esquemes de precodificació híbrida en escenaris d'interior, utilitzant diferents estratègies de desplegament i centrant l'atenció en els sistemes d' antenes distribuïdes (DAS). A més, es proposa un algoritme de precodificació híbrida distribuïda per a DAS, i s'avaluen i comparen les seues prestacions amb les de altres algoritmes. Per últim, s'investiga l'impacte de les limitacions pràctiques i altres deficiències introduïdes per l'ús de dispositius no ideals en les prestacions de tots els esquemes anteriors. Finalment, l' estudi de les UDNs es completa amb l'anàlisi de la seua principal limitació, el nivell creixent d'interferència entre cel·les. Per tractar aquest problema, es proposa un algoritme de control d'interferències basat en la partició de recursos. Les prestacions de l'algoritme proposat s'avaluen i comparen amb les d'altres tècniques d'assignació de recursos. Una vegada completat aquest estudi, es pot afirmar que les UDNs tenen un gran potencial per aconseguir els ambiciosos requeriments plantejats per a la 5G. Tanmateix, sense l'ús conjunt de majors amplàries de banda, apropiades tècniques de control de la interferència i l'ús massiu d'antenes, les UDNs poden convertir-se en seriosos obstacles per als operadors mòbils. Els resultats de l'avaluació de prestacions d' aquestes tecnologies confirmen el gran augment de la capacitat de les xarxes obtingut mitjançant l'ús massiu d'antenes i la introducci / Giménez Colás, S. (2017). Ultra Dense Networks Deployment for beyond 2020 Technologies [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86204

Les travaux présentés dans cette thèse sont une contribution à l’étude des systèmes d’imagerie active en bande millimétrique et plus spécifiquement sur les parties antennaires et le traitement de signal. Ces travaux ont été menés dans le cadre d’une collaboration entre Canon Research Center France et l’ETR. Une première étude a porté sur les antennes focalisantes et plus spécifiquement sur la lentille de Fresnel avec un procédé de fabrication de matériau à gradient d’indice qui a permis d’améliorer l’efficacité (59%) et la largeur bande de fréquence (75-110 GHz). Cette antenne a été utilisée sur un système rotatif pour imager une scène réelle extérieure. L’étude s’est ensuite focalisée sur la conception d’une configuration Multiple-Input Multiple-Output ou MIMO (entrées multiples, sorties multiples) grâce notamment à l’utilisation d’un dispositif compressif passif 4×1 permettant de réduire, par compression, le nombre de chaînes RF. Ces chaînes sont décompressées par post-traitement. Le dispositif, placé à l’émission, a été associé avec un scanner qui permet de synthétiser un réseau d’antennes à la réception. Cette configuration a permis de générer virtuellement un réseau de plus grande taille, permettant d’améliorer la résolution azimutale du système tout en limitant le nombre de chaînes RF. Cette configuration est utilisée pour imager une scène en chambre anéchoique afin de valider le concept. Pour améliorer encore plus la résolution du système avec un nombre limité de chaînes RF, l’étude d’algorithmes de haute-résolution, ou méthodes d’estimation spectrales, sont utilisés dans des configurations à large bande de fréquences pour imager des cibles en champs proche. L’association de la configuration MIMO, du dispositif compressif passif et des méthodes d’estimation spectrales permet d’améliorer la résolution du système tout en limitant le nombre de chaînes RF nécessaire. / The broad topic of the presented Ph.D. thesis consists in the contribution to the study of Radar imaging systems at millimeter-wave and more specifically to the antennas and signal processing. These works have been carried out during a partnership between Canon Research Center France and IETR. A first study on focusing antennas, particularly on Fresnel lens antennas, thanks to a technological process to manufacture inhomogeneous materials, has allowed to improve the efficiency and the frequency bandwidth. The antenna has been mounted on a rotary system to image a real outdoor scene. Then, the study has been focused on the realization of a Multiple-Input Multiple-Output (MIMO) configuration notably using a 4 × 1 passive compressive device allowing to reduce, by compression, the number of radiofrequency (RF) chains. The chains are decompressed by post-processing. The device, used at the transmitting part, is associated with a scanner that synthetizes a receiving array of antennas. This configuration allows to generate a large virtual array, to improve the azimutal resolution of the system while maintaining acceptable the number of RF chains. This configuration has been used to image a scene in an anechoid chamber to validate the concept. To further improve the spatial resolution of the system for a given number of RF chains, the study of high resolution algorithms, or spectral estimation methods, are used to image scenes in near field and wide-band configurations. The combination of MIMO configurations, the passive compressive device and the spectral estimation methods have allowed to drastically improve the spatial resolution of the radar imaging system while limiting the number of RF chains.

Vacuum microwave tubes, such as klystron, traveling-wave tube, gyrotron are high efficiency devices, where the RF interaction structure facilitates efficient energy transfer from the kinetic energy of the high energy electron beam to the electromagnetic wave. Traveling-wave Tube is the most versatile microwave power amplifier widely used for terrestrial communication, radar and aerospace applications. The waveguide based slow-wave structures like Millman, Karp, inter digital, grated waveguide, ring-plane, ring-bar, millitron and folded-waveguide structure gathered importance for application in millimeter-wave traveling-wave tubes. Among these millimeter-wave interaction structures, the folded-waveguide slow-wave structure became the most popular due to its robust structure, high power capability, low RF loss, simpler coupling, reasonably wide bandwidth and ease of fabrication for millimeter-wave to terahertz frequencies. Hence this thesis aims to analyse the folded-waveguide slow-wave structure for broad-banding and efficiency enhancement. The existing approaches for the analysis of cold circuit parameters (dispersion and interaction impedance characteristics) of folded-waveguide slow-wave structure are reinvestigated and found that these have limitation, as the effects of E-plane bend and beam-hole discontinuities are ignored in the parametric analysis. A cascaded matrix equivalent circuit model includes the effect of E-plane and beam-hole discontinuities for the analysis, but reported only for the serpentine folded-waveguide slow-wave structure. The cold test measurement technique was reported only for the dispersion characteristics. Hence the measurement technique has to be extended for the measurement of interaction impedance. The author proposes to orient the present doctoral work to (i) extend the proposed cascaded transmission matrix equivalent model for the analysis of rectangular folded-waveguide slow-wave structure, (ii) develop a non-resonant perturbation technique for the measurement of interaction impedance characteristics of the folded-waveguide slow-wave structure and also to (iii) establish new analysis models for the folded-waveguide slow-wave structure. The effect of E-plane bend and beam-hole discontinuities on the RF characteristics have been considered and simple, yet accurate closed form expressions for the computation of dispersion and interaction impedance characteristics have been established by three different approaches namely: transmission line equivalent circuit model, conformal mapping equivalent circuit model and quasi-TEM approach. The analysis results are benchmarked against 3-D electromagnetic modeling. The non-resonant perturbation theory is developed for the interaction impedance measurement. Typical Ka-band structures are fabricated by wire-EDM process and cold test measurements are carried out to benchmark the analysis approaches. The equivalent circuit models based on lumped circuit model are simpler than the cascaded matrix equivalent circuit model and can give closed form expressions for the prediction of dispersion and interaction impedance characteristics. The quasi-TEM approach can be extended for the complicated structure like ridge-loaded FWG-SWS. Broad-banding of the conventional folded-waveguide slow-wave structure is attempted by ridge-loading on the broad wall of the structure. The ridge-loaded folded-waveguide slow-wave structure is analyzed by parametric approach, cascaded transmission matrix equivalent circuit model and quasi-TEM approach and validated against numerical simulation. The analysis is extended for exploring the efficacy of the ridge-loading on broad-banding of the traveling-wave tube. Finally efficiency enhancement of the folded-waveguide slow-wave structure is attempted by introducing grating on the broad wall of the structure. The analysis is carried out by numerical simulation for exploring the efficacy of the grating on efficiency enhancement of the traveling-wave tube.

The evolution of the Home Area Network (HAN) is lead by the proliferation of connected devices inside the home and the deployment of high broadband access network which now allows the delivery of services that can exceed 1Gbit/s. To ensure efficient in-house exchanges, the HAN has to move rapidly toward multi-Gigabit/s connections, in particular the wireless connectivity generally preferred by the customers. Current wireless systems have limited capacities, but new radio standards delivering data-rates up to 7Gbit/s are emerging. Nevertheless, as they address the unlicensed millimeter-wave band, from 57 to 66 GHz, their radio coverage is limited to a single room. Indeed, at such frequencies, the free-space losses are high and the waves do not cross the walls. This thesis proposes to solve this problem by means of the Radio over Fiber (RoF) technology. This consists in capturing the 60GHz radio signals emitted in one room, converting them into optical signals for transmission through optical fibers, and reemitting them in another room. Thus, several RoF transducers will be installed in the home and interconnected by a suitable optical infrastructure to create systems acting at the same time as repeaters and as distribution systems. From the viewpoint of the HAN market, such systems will be competitive only if they are low cost. As a consequence, this work focuses on direct modulation with direct detection (IM-DD) at Intermediate Frequency (IF). In other words, the 60GHz signal is down-converted at a lower frequency around 5GHz before the laser modulation and up-converted to 60GHz after the photodetection. Concerning the optical fiber, silica multimode fiber (MMF) is privileged as it allows the use of low cost and largely available optoelectronic devices working at 850nm.The thesis proposes different RoF architectures, from point-to-point interconnecting two rooms to multipoint-to-multipoint acting as logical buses. After an analog characterization of the optoelectronic components, the RoF link and the domestic cable, these architectures are designed, built and characterized step by step using OFDM modulation according to existing wireless 60GHz standards. Real-time transmissions between commercial devices have also been performed to validate these architectures. Moreover, advanced RoF infrastructures are proposed. First, the RoF systems can be easily improved if the access to their optical media is managed by the radio MAC layer. This approach is therefore studied showing its feasibility. Secondly, an optical system, seen by users as a premium product, has to support the legacy home services commonly used as well as the new ones that could emerge in the future. Thus, innovative multiservice and multiformat infrastructures conveying on a unique optical cable wired IP data, broadcast terrestrial or satellite television, the 60GHz wireless connectivity, and specific formats as HDMI signals are proposed and tested

Three 40/60-GHz optical-wireless bidirectional architectures are designed with a centralized light source in the central office based on wavelength reuse. Three super-broadband access networks are proposed and experimentally demonstrated for simultaneously delivering wired and wireless services over an optical fiber and an air link in a single transport platform. The transport feasibility in metro and wide-area access networks with multiple reconfigurable optical add-drop multiplexers (ROADMs) nodes is explored for 40-GHz and 60-GHz optical millimeter-wave signals. Additionally, the optical-wireless systems using the orthogonal frequency division multiplexing (OFDM) modulation format are analytically and experimentally demonstrated to mitigate the chromatic dispersion in optical fiber. This thesis also successfully implements the testbed trial for the delivery of uncompressed 270-Mb/s standard-definition television (SDTV) and 1.485-Gb/s high-definition television (HDTV) video signals over optical fiber and air links. The demonstration represents the first ever reported real applications over hybrid wired and wireless access networks, showing that our developed up-conversion schemes and designed architectures are highly suitable for super-broadband applications in next-generation optical-wireless access networks.

[pt] A principal meta desta tese é estudar os efeitos da chuva nos enlaces operando na faixa de micro-ondas e comprimentos de ondas milimétricas. Para realizar este estudo, é considerado o modelo de chuva que considera um meio de chuva realista composto por um conjunto de gotas com a relação formato-tamanho proposta por Chuang e Beard, uma distribuição de tamanho das gotas dada por de Wolf, o índice de refração complexo da água para uma frequência e temperatura dada sugerido por Ray e uma distribuição de orientação dos eixos de simetria da partícula. O Extended Boundary Condition Method (EBCM) foi aplicado ao modelo descrito para determinar a atenuação, depolarização e espalhamento devidos à chuva. O desenvolvimento foi validado com sucesso por intermédio de comparações de seus resultados com os correspondentes disponíveis na literatura. O modelo de chuva realista foi utilizado em duas aplicações diferentes. Na primeira, foi estudada a interferência devida à chuva entre enlaces de telecomunicações sem fio operando em frequências de ondas milimétricas em ambientes urbanos. Outra aplicação envolve a determinação da taxa de precipitação por intermédio de radares meteorológicos (em particular, radares banda-X). Considerando que seu custo é relativamente baixo e sua resolução elevada, os radares em banda-X estariam entre as melhores opções para monitorar eventos meteorológicos. Entretanto, são susceptíveis à atenuação devida a gases atmosféricos e chuva ao longo dos enlaces, que impedem que a taxa de precipitação seja estimada diretamente a partir da potência recebida correspondente a uma determinada posição. Desta forma, um modelo de chuva realista foi implementado para calcular a seção reta de retroespalhamento e estimar a atenuação específica por intermédio do EBCM em cada um dos volumes existentes entre o radar e a posição selecionada. Este desenvolvimento permite a correção dos efeitos da atenuação existente no enlace formado entre estas duas posições. / [en] The main goal of this research is to study the rain effects on microwave and millimeter wave radio links. Thus, the rain-induced attenuation, depolarization and scattering are studied. To carry out this study, a realistic rain model is proposed, which consider a realistic rain medium composed by a cluster of raindrops with the shape-size relation proposed by Chuang and Beard, a raindrop size distribution given by de Wolf, index of refraction of water for a given temperature and frequency suggested by Ray and a distribution of the orientation angle of the symmetry axis. The realistic rain model is evaluated with two different applications of systems operating at microwave and millimeter wave frequencies. One of the applications involves wireless telecommunication systems, which are strongly affected by the presence of precipitation. To design an efficient radio communication system, the realistic rain model is applied for the analysis and quantification of rain-induced effects on links operating at millimeterwave frequencies in urban environments. Another application involves weather radars (X-band radars in particular). Considering their relatively low cost and high resolution, X-band radars would be among the best options to monitor meteorological events. However, they are susceptible to attenuation by fog, snow or rain. To solve this problem, a realistic and improved rain model is implemented to compute backscattering cross sections and estimate rain attenuation at each range gate. The proposed method is evaluated using radar data provided by the CASA OTG X-band (lambda equal a 3cm) radar located in Mayaguez, Puerto Rico, and X-band radar METEOR 50DX –Selex located in Belém, Brazil.

Orientador: Jacobus Willibrordus Swart / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T12:44:03Z (GMT). No. of bitstreams: 1 Yamamoto_SilasDemmy_M.pdf: 5306597 bytes, checksum: 9dd3930c43415f31bf913b4d374c25eb (MD5) Previous issue date: 2011 / Resumo: O trabalho intitulado Integração de Sistema Transceptor de 60 GHz para Aplicações Sem Fio de Interface Multimídia de Alta Definição (Wireless HDMI) foi realizado na empresa STMicroelectronics (França), no departamento de P&D de Tecnologia / CAD Central e Soluções, como requisito para a obtenção do título de mestre. O objetivo deste trabalho foi de pesquisar e propor uma integração de sistema do tipo Sistema no Empacotamento (SiP ou System in Package) a nível industrial, com o desenvolvimento de um Módulo de Múltiplos Chips (MCM ou Multi-Chip Module) de camadas cerâmicas com tecnologia Cerâmica Cossinterizada sob Alta Temperatura (HTCC), integrando componentes de diferentes tecnologias - um circuito integrado CMOS 65 nm, um circuito integrado monolítico de micro-ondas (MMIC) de Arseneto de Gálio (GaAs) comercial e antenas IPD (Dispositivo de Integração Passiva) de vidro. Além disso foram desenvolvidas técnicas de projeto de integração na tecnologia HTCC, atendendo-se às regras para fabricação e montagem industrial. Utilizaram-se no projeto ferramentas software de projeto de simulação elétrica e eletromagnética, resultando no módulo com área de 13 x 8 mm2 e 1,12 mm de espessura incluindo os componentes. Nas linhas de transmissão do sinal a 60 GHz e de banda base foram medidas perdas de inserção de 1,0 dB/mm e 0,6 dB respectivamente. A antena integrada no módulo apresentou um ganho mínimo de 6 dBi (de 53,5 a 59,5 GHz), com perda de retorno maior que 10 dB (de 51 a 63 GHz) e um pequeno deslocamento em relação à banda especificada. Os resultados de medição de algumas amostras demonstraram que a tecnologia HTCC, para integração do sistema, é viável tanto em termos de desempenho, quanto nos aspectos industrial e comercial, mesmo antes da análise da montagem e desempenho do MMIC HPA e do sistema / Abstract: This Master's degree work, entitled System-in-Package (SiP) Integration of 60 GHz Transceiver for Wireless High Definition Multimedia Interface Application, was executed at STMicroelectronics Company (France), Minatec site in the department of Research and Technological Development/Central CAD and Solutions Department, under the guidance of PhD. Andreia Cathelin. The objective was to research and propose a SiP integration for industrial production. The Multi-Chip Module with ceramic materials (MCM-C) of High Temperature Cofired Ceramic technology (HTCC) was developed. Components and devices of different technologies - an RF 65 nm CMOS Integrated Circuit (IC), a commercial Gallium Arsenide (GaAs) monolithic microwave IC (MMIC), and IPD (Integrated Passive Device) antennas with glass substrate - were integrated into the same module. Further design techniques were developed complying with techniques for industrial assembly and the design rules of Kyocera, the company which provides HTCC technology and module manufacturing. The complete system integration was designed with electronic design automation (EDA) software tools with electrical and electromagnetic simulation resulting in a 13 x 8 mm2 area and 1.12 mm thickness module including its components. The 60 GHz and the base band transmission lines presented an insertion loss of 1.0 dB/mm and 0.6 dB respectively. The IPD antenna integrated in the module presented a 6 dBi minimum gain (53.5 to 59.5 GHz band) with return loss above 10 dB (51 to 63 GHz band) and a small shift of the frequency band. The measurement results of some assembled samples showed that HTCC technology is viable in terms of performance and industrial production for the 60 GHz application, even before the analysis of MMIC HPA and the system evaluation / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica