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).

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006. / The topic of millimeter wave radar systems is introduced. These radars are used in a wide range of applications in both the aviation and automotive field due to the resolution advantages which MMW systems have above their counterparts. MMW components are studied and characterised to improve on an existing linearisation technique. Different possible linearisation techniques are discussed and compared to choose the best possible technique for this application. This technique was developed and implemented in the existing system.

The rotational spectrum of ScO (X-2 Sigma(+)) has been measured in the gas phase in the frequency range 30-493 GHz using a combination of Fourier transform microwave/millimeter-wave (FTM/mmW) and submillimeter direct absorption methods. This work is the first pure rotational study of this radical. Both the ground vibrational and v=1 states were observed. ScO was created from the reaction of metal vapor, produced either by a laser ablation source or a Broida-type oven, and N2O, in the former case heavily diluted in argon. Extensive hyperfine structure was observed in the FTM/mmW data, although the spin-rotation splitting was found to be small (similar to 3 MHz). In the mm-wave spectra, however, the fine and hyperfine structure was blended together, resulting in broad, single lines for a given transition N + 1 <- N. The data were analyzed in a combined fit using the very accurate hyperfine measurements of Childs and Steimle (1988), employing a Hund's case b Hamiltonian, and an improved set of rotational and centrifugal distortion constants were determined. These measurements improve the accuracy of predicted frequencies for astronomical searches by 14-18 MHz, or 16-20 km/s, in the 1 mm region - a difference of half to a full linewidth for certain interstellar sources. This work also demonstrates the capabilities of the FTM/mmW spectrometer at 61 GHz.

This thesis presents the development of various methods for measuring rainfall rates using horizontally-pointing millimetre-wave radars. This work builds from the combination of a T-matrix scattering model that allows the scattering from almost arbitrarily pro led rotationally symmetric particles to be calculated, and drop shape models that allow the effects of temperature and pressure on the shape to be taken into account. Many hours of rain data have been collected with 38 and 94 GHz FMCW radars, as well as with a disdrometer and weather station. These have been used to develop single- and dual-frequency techniques for measuring rainfall rate. A temperature, polarisation and attenuation corrected application of simple power-law relationships between reflectivity and rainfall rate has been successfully demonstrated at 38 GHz. However, at 94 GHz it has been found that more detailed functions relating reflectivity, attenuation and rainfall rate are beneficial. A reflectivity-based determination of attenuation has been adapted from the literature and successfully applied to the 94 GHz data, improving the estimate of rainfall rate at longer ranges. The same method for estimating attenuation has also been used in a dualfrequency technique based on the ratio of the extinction coefficients at 38 and 94 GHz, but with less success. However, a dual-frequency reflectivity ratio based approach has been successfully developed and applied, producing good estimates of rainfall rate, as well as reasonable estimates of two drop-size distribution parameters. Simulations of radar measurements of airborne volcanic ash have also been carried out, demonstrating that for most reasonable measurement configurations the optimal frequencies would typically be 35 GHz or 94 GHz, not the more commonly used 3-10 GHz. It has also been shown that various existing millimetre-wave radars could be used to detect ash. Finally, there is a discussion of the optimal frequencies for dual-frequency measurement of volcanic ash.

The thesis presents a compact, miniature, and low cost antenna array designed for millimeter-wave frequencies for future 5th generation (5G) mobile applications. The proposed antenna array is a geometrically modified structure of the Franklin array, which allowed to transform a conventional narrowband array into a wideband antenna array. It is composed of five millimetre-wave circular patch radiation elements with phasing stubs. The designed array, fabricated on the commercial Rogers RO3003 substrate with small form factor of 8x25x0.5 mm3, covers the upcoming 5G band of 23.6-30.3 GHz, with peak gain as 10.8 dB, and high radiation efficiency over the whole operating band. In addition, with frequency sweeping, the proposed antenna array radiation pattern is directive and offers beam steering at the desired angles, acting similarly as a leaky-wave antenna.

Introdução- A busca ativa de indivíduos infectados pelo Mycobacterium tuberculosis, com o auxílio do teste tuberculínico, principalmente em populações de detentos, moradores de rua, infectados pelo vírus do HIV entre outras, tem como objetivo prevenir a evolução da infecção para a doença tuberculose e auxiliar o conhecimento de novos casos da doença. O teste tuberculínico é uma importante ferramenta, para identificar os indivíduos reatores (infectados) e não reatores (não infectados). Ele pode ser aplicado a partir de várias técnicas, mas a que permite a padronização e a comparação dos resultados é a técnica intradérmica de Mantoux, a mais usada atualmente. No Brasil, a leitura do resultado do teste tuberculínico é realizada, por recomendação do Ministério de Saúde, com régua milimetrada. Para seu uso é necessário um treinamento rigoroso, o que tem contribuído para a diminuição de leitores do teste tuberculínico na rotina dos serviços de saúde. Como alternativa temos outro instrumento, paquímetro, ainda não padronizado no Brasil. Outros países o utilizam nas rotinas dos serviços de saúde para busca de indivíduos reatores ou não ao teste tuberculínico, ele não cabe para aferição ou inquéritos epidemiológicos. Objetivo- Comparar os instrumentos de leitura dos resultados do teste tuberculínico obtidos através da leitura padronizada, feita por régua milimetrada, e a leitura, não padronizada, feita por paquímetro. Métodos- Estudo descritivo realizado numa população prisional de uma Penitenciária e de um Centro de Detenção Provisória, da cidade de Guarulhos, Grande São Paulo, entre os meses de março a junho de 2008. Foi realizada a leitura do teste tuberculínico de forma dupla cega, por dois leitores, com instrumentos diferentes, paquímetro e régua milimetrada. Resultados- Foram administrados testes tuberculínicos em 1954 indivíduos; destes 111 foram excluídos por não terem comparecido à leitura do teste, resultando em uma amostra de 1843 indivíduos divididos em 1059 (57,5 por cento ) na Penitenciária e 784 (42,5 por cento ) no Centro de Detenção Provisória. Os resultados comparativos entre os dois instrumentos, quando avaliados os reatores com os não reatores, foram altos e equivalentes, pois a sensibilidade (93 por cento ) e a especificidade (97 por cento ) foram praticamente as mesmas. A média da concordância foi alta entre os dois instrumentos (95,5 por cento ) e a discordância foi baixa (4,5 por cento ). O Ministério da Saúde preconiza uma concordância acima de 80 por cento para aferição de novos leitores. Conclusões- Com este estudo observamos que o paquímetro pode ser considerado equivalente à régua milimetrada e poderá ser uma alternativa à régua para a leitura do teste tuberculínico no Brasil, principalmente para a busca de casos de tuberculose latente na rotina dos serviços de saúde, por ser um bom instrumento de separação dos indivíduos e não é suficiente para aferir um novo leitor. Entretanto, a régua deverá ser mantida, especialmente para inquéritos epidemiológicos / Introduction- The active search of individuals infected with Mycobacterium tuberculosis aims to prevent the development of infection to the disease tuberculosis and ancillary knowledge of new cases of the disease. The tuberculin test is an important tool to identify individuals (infected) and non-reactors reactors (noninfected). It can be applied from various techniques. Nowadays Mantoux intradermal technique is the most widely used and allows the standardization and comparability of results. In Brazil, the reading of the tuberculin test result is performed with a ruler, by recommendation of the Ministry of health. For its use is required a rigorous training, which has contributed to the decline of tuberculin test readers in routine health services. Alternatively, caliper rule is a technique that can be used, but it is not standardized in Brazil. Objective- Compare the reading instruments of tuberculin skin test results obtained through the standardized reading, made by a millimeter ruler, and reading, not standardized, made with a caliper rule. Method- It was a descriptive study in a prison population of a Penitentiary and a Provisional Detention Centre in the city of Guarulhos, São Paulo, between the months of March to June 2008. Tuberculin test reading was done in a double blind, tuberculin test by two readers, with different instruments, ruler and caliper rule. Results- Tuberculin skin tests were administered to 1,954 individuals; of these 111 was excluded for failing to appear for the reading test, resulting in a sample of 1,843 individuals divided in 1,059 (57.5 per cent ) in Penitentiary and 784 (42.5 per cent ) in the Provisional Detention Center. The comparative results between the two instruments were high and equivalent (sensitivity=93 per cent and specificity=97 per cent ). The average correlation was high among the two instruments (95.5 per cent ) and the disagreement was low (4.5 per cent ). The Ministry of Health recommends a concordance above 80 per cent for benchmarking new readers. Conclusions- We observed that the caliper rule can be considered equivalent to the rule and may be an alternative for reading the tuberculin test in Brazil, especially to search for latent TB cases. However, the rule should be maintained, especially toepidemiological investigations

Este trabalho, realizado junto ao Grupo de Novos Materiais e Dispositivos (GNMD) pertencente ao Laboratório de Microeletrônica (LME) da Universidade de São Paulo, teve como objetivo correlacionar algumas propriedades físico-químicas de filmes finos de Ba1-XSrxTiO3 (BST), obtidos pela técnica de pulverização catódica reativa (sputtering), com os parâmetros de deposição, visando a fabricação de defasadores inteligentes operando em 60 GHz. Propriedades como cristalinidade e composição química foram estudadas e relacionadas com o tipo de substrato sobre o qual os filmes finos de BST foram depositados, e com os diversos parâmetros de deposição variados. Foi observada uma forte influência dos parâmetros de deposição, principalmente da temperatura e do tipo de substrato, na cristalinidade dos filmes. Os filmes depositados sobre cobre são mais cristalinos do que aqueles depositados sobre Si. Já a composição química dos filmes não variou significativamente, mantendo-se próxima à do alvo de sputtering utilizado, independentemente do substrato ou das condições de deposição. As propriedades elétricas dos filmes fabricados foram extraídas de capacitores de placas paralelas construídos utilizando o BST como dielétrico linear. As curvas de capacitância vs tensão a 1 MHz destes capacitores permitiram determinar uma variação de tunabilidade de até 44 %, para uma permissividade elétrica relativa de 310, valores estes compatíveis com aqueles encontrados na literatura. As propriedades elétricas dos filmes produzidos permitiram projetar um defasador de 1,3 mm2, com uma figura de mérito de 30º/dB para uma defasagem de 360º. / This work, performed at the New Materials and Devices Group (GNMD) of the Microelectronics Laboratory of the Polytechnic School of the University of São Paulo, has the objective to correlate reactive sputtered-BST thin films to its deposition parameters, aiming to produce a 60 GHz tunable phase shifter. Thin film crystallinity and stoichiometry were correlated with sputtering deposition parameters and the type of substrate. A strong influence of the sputtering parameters was observed on BST crystallinity, mainly the temperature and the type of substrate. Thin films on copper are more crystalline than on Si (100). The stoichiometry, on the other hand, did not change as function of the deposition parameters or the substrate in both cases. The thin films electrical properties were obtained by capacitance vs voltage measurements, with the BST as linear dielectric of a parallel plate capacitor. The capacitors 1 MHz C-V characterization showed tunabilities as high as 44%, for an electrical permittivity of 310. These properties allowed a phase shifter project, resulting a 1,3 mm2 device with a figure of merit of 30 º/dB for 360 º phase shift.

Les futurs systèmes de communication utiliseront des porteuses de fréquences d'ondes millimétriques (mm) (30 GHz - 300 GHz) et au-delà pour surmonter la saturation des différentes bandes de fréquence et atteindre des débits élevés. Les systèmes radio sur fibre (RoF) ont attiré l'attention grâce à leur faible coût et à la faible atténuation des fibres. Dans le cadre de cette thèse, différentes configurations et plusieurs conceptions de lasers ont été proposées pour la génération de fréquences radio par voie optique. L’amélioration du processus de fabrication de laser développé au laboratoire a permis d’obtenir des sources monomodes émettant autour du pic d'erbium (1534 nm) jusqu'à des puissances optiques de sortie de 41 mW avec une efficacité de 9,8%. Leurs largeurs de raie optiques ont été mesurée égales à 2 kHz et leur bruit d’intensité relatif (RIN) égal à -145 dB/Hz après 50 MHz. Avec ces lasers, des signaux électriques à des fréquences millimétriques de largeur de raie de quelques kHz ont été générés. Trois configurations hétérodynes ont été proposées pour améliorer la stabilité thermique des signaux générés afin de répondre aux normes IEEE. Des lasers co-intégrés ont été de plus fabriqués pour générer des porteuses comprises entre 5GHz et 165GHz. Une étude comparative a montré que les comportements des porteuses ainsi générées étaient indépendants de la fréquence produite. Enfin, les conceptions de structures intégrant coupleur, adaptation de modes et de plusieurs lasers sur verre pompés par une unique source ont été étudiées. En utilisant les porteuses générées par ces dernières réalisations, des transmissions de données ont été accomplies répondant aux normes requises. / Future communication systems will use millimeter-wave (mm) (30 GHz - 300 GHz) frequency carriers and beyond to overcome the saturation of different frequency bands and achieve high data rates. Radio-over-Fiber (RoF) systems have gained attention thanks to their low cost and low fiber attenuation. In this thesis, different configurations and several laser designs have been proposed for radio frequency generation by photonic based technique. The Improvement of the laser fabrication process developed in the laboratory resulted in single-mode sources emitting around the erbium peak (1534 nm) up to 41 mW optical output power with 9.8% efficiency. Their optical linewidths were measured equal to 2 kHz and their relative intensity noise (RIN) equal to -145 dB/Hz after 50 MHz. Using these lasers, electrical signals at millimeter frequencies having linewidths of few kHz have been generated Three heterodyning configurations have been proposed to improve the thermal stability of the generated signals in order to meet the IEEE standards. Co-integrated lasers have been further manufactured to generate carriers between 5GHz and 165GHz. A comparative study showed that the behaviors of the carriers thus generated were independent of the produced frequency. Finally, the designs of structures integrating coupler, tapers and several lasers on glass pumped by a single source were studied. By using the carriers generated by these latest implementations, data transmissions have been accomplished meeting the required standards.

The smart environments and the connected human seems to be the future of wireless communications. The development of new frequency bands in the millimeter range will allow us to create high data rate communications which will led to the Wireless Body Environment Networks. In this kind of scenarios, it is expected that the user and the environment will interact. In order to develop such new applications, it is necessary to first study the propagation mechanisms and then, the communication channel underlying body centric environments. This thesis treats of channel models for 60 GHz Body Area Networks and more particularly of three kinds of scenarios: (i) the communication between an external base station and a worn node (off-body); (ii) the communication between two worn nodes (on-body); the communication between an external base station and a hand-held device (near-body). An indoor off-body channel model is numerically proposed and implemented. The model is based on the IEEE 802.11ad indoor standard channel at 60 GHz and a fast computation solution of the scattering of a plane wave by a circular cylinder. The model is developed for two orthogonal polarizations and the communications performances are studied. The on-body propagation is studied for two different configurations: line-of-sight and non-line-of-sight communications on the body. These scenarios led to different solutions for the channel knowing as, respectively, Norton’s equations and creeping formulations. These solutions are obtained using simplified geometries which has been experimentally validated. Further, in order to improve the propagation on the human body, a technique using metallic plates has been proposed. This technique has been theoretically studied using Milligton’s equations and experimentally assessed on a flat phantom with the properties of the human skin. The proposed method allows to save up to 20 dB. Finally, the near-body communication scenario has been introduced and studied. The near-body region is extended from 5 to 30 cm away of the user body which corresponds to the arm’s reach and models a handheld device. A numerical algorithm has been proposed to model indoor near-body environments. Also, a special has been given to statistical body shadowing. It has been shown that the fading follows a Two-Wave Diffuse Power distribution. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Compressive Sensing (CS) is a recently proposed signal processing technique that has already found many applications in microwave and millimeter-wave imaging. CS theory guarantees that sparse or compressible signals can be recovered from far fewer measure- ments than those were traditionally thought necessary. This property coincides with the goal of personnel surveillance imaging whose priority is to reduce the scanning time as much as possible. Therefore, this thesis investigates the implementation of CS techniques in personnel surveillance imaging systems with different array configurations. The first key contribution is the comparative study of CS methods in a switched array imaging system. Specific attention has been paid to situations where the array element spacing does not satisfy the Nyquist criterion due to physical limitations. CS methods are divided into the Fourier transform based CS (FT-CS) method that relies on conventional FT and the direct CS (D-CS) method that directly utilizes classic CS formulations. The performance of the two CS methods is compared with the conventional FT method in terms of resolution, computational complexity, robustness to noise and under-sampling. Particularly, the resolving power of the two CS methods is studied under various cir- cumstances. Both numerical and experimental results demonstrate the superiority of CS methods. The FT-CS and D-CS methods are complementary techniques that can be used together for optimized efficiency and image reconstruction. The second contribution is a novel 3-D compressive phased array imaging algorithm based on a more general forward model that takes antenna factors into consideration. Imaging results in both range and cross-range dimensions show better performance than the conventional FT method. Furthermore, suggestions on how to design the sensing con- figurations for better CS reconstruction results are provided based on coherence analysis. This work further considers the near-field imaging with a near-field focusing technique integrated into the CS framework. Simulation results show better robustness against noise and interfering targets from the background. The third contribution presents the effects of array configurations on the performance of the D-CS method. Compressive MIMO array imaging is first derived and demonstrated with a cross-shaped MIMO array. The switched array, MIMO array and phased array are then investigated together under the compressive imaging framework. All three methods have similar resolution due to the same effective aperture. As an alternative scheme for the switched array, the MIMO array is able to achieve comparable performance with far fewer antenna elements. While all three array configurations are capable of imaging with sub-Nyquist element spacing, the phased array is more sensitive to this element spacing factor. Nevertheless, the phased array configuration achieves the best robustness against noise at the cost of higher computational complexity. The final contribution is the design of a novel low-cost beam-steering imaging system using a flat Luneburg lens. The idea is to use a switched array at the focal plane of the Luneburg lens to control the beam-steering. By sequentially exciting each element, the lens forms directive beams to scan the region of interest. The adoption of CS for image reconstruction enables high resolution and also data under-sampling. Numerical simulations based on mechanically scanned data are conducted to verify the proposed imaging system.