In this study, the Dual Beam Phased Array Antenna System designed for COST260* project is upgraded to have the abilities of beam steering, tracking and direction finding by providing the necessary computer codes using C++ Programming Language. The functions of new prototype are tested to verify the operation. *COST260 project was an adaptive phased array receiving antenna system for satellite communication, which was operating at 11.49-11.678 GHz band.

In this dissertation, a carbon nanotube thin-film transistor is fabricated on a flexible substrate. Combined printing and stamping techniques are used for the fabrication. An ink-jet printing technique is used to form the gate, source, and drain electrodes as well as the dielectric layer. A self aligned carbon nanotube (CNT) thin film is formed by using a new modified dip coat technique before being transferred to the device substrate. This novel modified dip-coat technique utilizes the capillary effect of a liquid solution rising between gaps to coat CNT solution on a large area of the substrate while consuming minimal CNT solution. Several key solutions are addressed to solve the fabrication problems. (1) The source/drain contact with the CNT channel is developed by using droplets of silver ink printed on the source/drain areas prior to applying CNT thin. The wet silver ink droplets allow the silver to "wet" the CNT thin-film area and enable good contact with the source and drain contact after annealing. (2) A passivation layer to protect the device channel is developed by bonding a thin Kapton film on top of the device channel. This thin Kapton film is also used as the media for transferring the aligned CNT thin-film on the device substrate. Using this technique, printing the passivation layer can be avoided, and it prevents the inter-diffusion of the liquid dielectric into the CNT porous thin-film. (3) A simple and cost effective technique to form multilayer metal interconnections on flexible substrate is developed and demonstrated. Contact vias are formed on the second substrate prior bonding on the first substrate. Ink-jet printing is used to fill the silver ink into the via structure. The printed silver ink penetrates through the vias to contact with the contact pads on the on the bottom layer, followed by an anneal process. High drain current of 0.476mA was obtained when V[subscript G]= -3V and source-drain voltage (V[subscript DS]) was -1.5V. A bending test was performed on the CNT TFT showing less than a 10% variation in performance. A bending test was also performed on via structures, which yielded less than a 5% change in resistance. The developed CNT TFT is used to form a switch in a phase shifter for a flexible phased-array antenna (PAA). Four element 1-dimensional and 2-dimensional phased-array antennae are fabricated and characterized. Multilayer metal interconnects were used to make a complete PAA system. For a 2-bit 1x4 PAA system, by controlling the ON/OFF states of the transistors, beam steering of a 5.3GHz signal from 0° to -27° has been demonstrated. The antenna system also shows good stability and tolerance under different bending radii of curvature. A 2-bit 2x2 PAA system was also fabricated and demonstrated. Two dimensional beam steering of a 5.2GHz signal at an angle of [theta]=20.7° and [phi]=45° has been demonstrated. The total efficiency of the 1-dimensional and 2-dimensional PAA systems are 42% and 46%, respectively. / text

Phased array antenna (PAA) is a key component in many of the modern military and commercial radar and communication systems requiring highly directional beams with narrow beam widths. One of the advantages that this technology offers is a physical movement-free beam steering. Radar and communication technologies also require the PAA systems to be compact, light weight, demonstrate high bandwidth and electromagnetic interference (EMI) free performance. Conventional electrical phase shifters are inherently narrowband. This calls for technologies that have a larger bandwidth and high immunity to electromagnetic interference. Optical true-time-delay (TTD) technique is an emerging technology that is capable of providing these features along with the ability to provide frequency independent beam steering. Photonic crystal fiber (PCF) based optical TTD lines are capable of providing precise and continuous time delays required for PAA systems. Photonic crystal fibers are a new class of optical fibers with a periodic arrangement of air-holes around a core that can be designed to provide extraordinary optical characteristics which are unrealizable using conventional optical fibers. In this dissertation, highly dispersive photonic crystal fiber structures based on index-guidance and bandgap-guidance were designed. Designs exhibiting dispersion coefficients as large as -9500ps/nm/km and 4000ps/nm/km at 1550nm were presented. A TTD module utilizing a fabricated highly dispersive PCF with a dispersion coefficient of -600ps/nm/km at 1550nm was formed and characterized. The module consisted of 4 delay lines employing highly dispersive PCFs connected with various lengths of non-zero dispersion shifted fibers. By employing PCFs with enhanced dispersion coefficients, the TTD module size can be proportionally reduced. A 4-element linear X-band PAA system using the PCF-TTD module was formed and characterized to provide continuous time delays to steer radiofrequency (RF) beams from -41 degrees to 46 degrees by tuning the wavelength from 1530nm to 1560nm. Using the PCF-TTD based X-Band PAA system, single and simultaneous multiple beam transmission and reception capabilities were demonstrated. Noise and distortion performance characteristics of the entire PAA system were also evaluated and device control parameters were optimized to provide maximum spurious-free-dynamic range. In order to alleviate computational and weight requirements of practical large PAA systems, a sparse array instead of a standard array needs to be used. X-Band sparse array systems using PCF and dispersive fiber TTD technique were formed and RF beam steering was demonstrated. As an important achievement during the research work, the design and fabricated structure of a PCF currently reported to have the highest dispersion coefficient of -5400ps/nm/km at 1549nm, along with its limitations was also presented. Finally, other interesting applications of highly dispersive PCFs in the areas of pulse compression and soliton propagation were explored. / text

A tunable snapshot imaging spectrometer has been demonstrated. A liquid crystal spatial light modulator (LC SLM) has been integrated into a computed tomographic imaging spectrometer (CTIS) to achieve tunability. The LC SLM allows for rapid, programmable, and non-mechanical alteration of its phase profile by the application of appropriate voltages to its transparent electrodes.The goal of this dissertation is twofold: (1) to integrate a liquid crystal spatial light modulator into a CTIS instrument and characterize its performance as a tunable CTIS disperser, and (2) to implement tunability by analyzing different CTIS configurations.The theoretical model of CTIS operation, calibration, reconstruction, and disperser design are covered in detail. The cross talk of the LC SLM forces the use of a feedback design algorithm rather than designing the desired phase profile a priori in the computer. The modifications to the current polychromatic linear inversion technique for use with the LC SLM in feedback are presented. The result of the modifications is the successful integration of a reprogrammable (i.e. tunable) disperser for the CTIS instrument.The implementation of tunability is explored by analyzing the spectral resolution of a reconstructed point source for different disperser configurations. A method for experimentally determining the CTIS spectral resolution is presented.

Current technology used to diagnose hearing disorders is limited. This is mostly due to the fact that the auditory structures are very small and not easily accessible with existing imaging technologies. The objective of this dissertation was to investigate the potential of high-frequency ultrasound as a tool for exploring the anatomy of the auditory system. Three studies were conducted in order to demonstrate the feasibility of high-frequency ultrasound as a diagnostic technology for hearing disorders. In the first study, an in-house developed 50 MHz annular array-based ultrasound system was used to provide ex-vivo images of auditory structures in cadaveric temporal bones. It was shown that the spatial resolution was sufficient to visualize a high level of detail of the ossicular bones of the middle ear as well as intra-cochlear structures of the inner ear. In the second study, a 50 MHz 1.26? pitch phased array ultrasound transducer was designed for imaging intra-cochlear structures through the round window membrane. As this element pitch results in large grating lobe artifacts, novel transmit beamforming techniques were developed to suppress grating lobes resulting from this large-pitch array. Theoretical techniques using the impulse-response simulation method and experimental verification using high-frequency linear array ultrasound system (Vevo 2100, VisualSonics, Canada) showed that these techniques were able to suppress grating lobe levels up to 40 dB. In the third study, a needle mounted 45 MHz single-element ultrasound probe was fabricated in order to measure the vibrations of intra-cochlear structures on human cadavers. Basilar membrane velocimetry measurements were successfully performed using pulsed-wave Doppler ultrasound in the frequency range between 100 Hz-2 KHz. The measured velocity of the basilar membrane and the round window membrane showed that the middle ear resonance frequency near 1 KHz was present over multiple temporal bones. This is the first work that has explored the human auditory system with high resolution ultrasonic visualization and Doppler velocimetry.

The goal of the research reported in this thesis is to establish the feasibility of a novel optical architecture for an optical route & select circuit switch suitable for implementation as a photonic integrated circuit. The proposed architecture combines Optical Phased Array (OPA) switch elements implemented as multimode interference coupler based Generalised Mach-Zehnder Interferometers (GMZI) with a planar Lüneburg lens-based optical transpose interconnection network implemented using graded metamaterial waveguide slabs. The proposed switch is transparent to signal format and, in principle, can have zero excess insertion loss and scale to large port counts. These switches will enable the low-energy consumption high capacity communications network infrastructure needed to provide environmentally-friendly broadband access to all. The thesis first explains the importance of switch structures in optical communications networks and the difficulties of scaling to a large number of switch ports. The thesis then introduces the Talbot effect, i.e. the self-imaging of periodic field distributions in free space. It elaborates on a new approach to finding the phase relations between pairs of Talbot image planes at carefully selected positions. The free space Talbot effect is mapped to the waveguide Talbot effect which is fundamental to the operation of multimode interference couplers (MMI). Knowledge of the phase relation between the MMI ports is necessary to achieve correct operation of the GMZI OPA switch elements. An outline of the design procedures is given that can be applied to optimise the performance of MMI couplers and, as a consequence, the GMZI OPA switch elements. The Lüneburg Optical Transpose Interconnection System (LOTIS) is introduced as a potential solution to the problem of excessive insertion loss and cross-talk caused by the large number of crossovers in a switch fabric. Finally, the thesis explains how a Lüneburg lens may be implemented in a graded ‘metamaterial’, i.e. a composite material consisting of ‘atoms’ arranged on a regular lattice suspended in a host by nano-structuring of silicon waveguide slabs using a single etch-step. Furthermore, the propagation of light in graded almost-periodic structures is discussed. Detailed consideration is given to the calibration of the local homogenised effective index; in terms of the local parameters of the metamaterial microstructure in the plane and the corrections necessary to accommodate slab waveguide confinement in the normal to the plane. The concept and designs were verified by FDTD simulation. A 4×4 LOTIS structure showed correct routing of light with a low insertion loss of -0.25 dB and crosstalk of -24.12 dB. An -0.45 dB excess loss for 2D analysis and an -0.83 dB insertion excess loss for 3D analysis of two side by side metamaterial Lüneburg lenses with diameter of 15 μm was measured, which suggests that the metamaterial implementation produces minimal additional impairments to the switch.

In this thesis, based on the indoor channel measurements and ray-tracing modeling for the indoor mm-wave wireless communications, the challenges of the design of the radio in this band is studied. Considering the recently developed standards such as IEEE 802.15.3c, ECMA and WiGig at 60 GHz, the link budget of the system design for different classes of operation is done and the requirement for the antenna and other RF sections are extracted. Based on radiation characteristics of mm-wave and the fundamental limits of low-cost Silicon technology, it is shown that phased-array is the ultimate solution for the radio and physical layer of the mobile millimeter wave multi-Gb/s wireless networks. Different phased-array configurations are studied and a low-cost single-receiver array architecture with RF phase-shifting is proposed. A systematic approach to the analysis of the overall noise-figure of the proposed architecture is presented and the component technical requirements are derived for the system level specifications. The proposed on-chip antennas and antenna-in-packages for various applications are designed and verified by the measurement results. The design of patch antennas on the low-cost RT/Duroid substrate and the slot antennas on the IPD technologies as well as the compact on-chip slot DRA antenna are explained in the antenna design section. The design of reflective-type phase shifters in CMOS and MEMS technologies is explained. Finally, the design details of two developed 60 GHz integrated phased-arrays in CMOS technology are discussed. Front-end circuit blocks such as LNA, continuous passive reflective-type phase shifters, power combiner and variable gain amplifiers are investigated, designed and developed for a 60 GHz phased-array radio in CMOS technology. In the first design, the two-element CMOS phased-array front-ends based on passive phase shifting architecture is proposed and developed. In the second phased-array, the recently developed on-chip dielectric resonator antenna in our group in lower frequency is scaled and integrated with the front-end.

A routine non-destructive test method based on Phased Array Ultrasonic Testing (PAUT) has been developed and applied for the inspection of the first 11 T dipole prototype magnet half shell welds, and the test results are compared with the radiography and visual inspection results of the same welds. A manual scanner and alignment system have been developed and built to facilitate the inspection of the 5.5 m long welds, and to assure reproducibility of the PAUT results. Through the comparison of distance readings and signal amplitude for different focus lengths, a focal law with focus at 25 mm sound path has been selected for the routine inspection of the 15 mm thick austenitic stainless steel 11 T dipole welds. The defocusing properties (beam spread) due to the cylindrical geometry of the half shells and the sound path distance to the area of interest were taken into account. Dedicated sensitivity calibration weld samples with artificial defects (side-drilled-holes) have been designed and produced from 11 T dipole prototype austenitic stainless steel half shell welds. These provide representative calibration for the strongly attenuating and scattering austenitic stainless steel weld material. One scan with two phased array probes aligned parallel to the weld in 2 mm distance from the weld cap edge, and one scan with the probes aligned parallel to the weld in 12 mm distance from the weld cap edge are sufficient to show if the inspected welds fulfil the requirements of weld quality level B according to ISO 5817. The standard test duration for the two scans of the two 5.5 m long horizontal welds of the 11 T dipole magnets is about one day, provided that no defects are found that need to be characterized in more detail.

[pt] Este trabalho de Tese apresenta a pesquisa, dimensionamento e desenvolvimento de lentes de Rotman em microstrip. É apresentada uma nova metodologia para projetos com apoio de ferramentas computacionais de simulação eletromagnética. São desenvolvidos protótipos em substratos dielétricos (permissividade relativa igual 10,2) para aplicações de direcionamento eletrônico de feixe (phased array) nas faixas de frequências de radares e sistemas de defesa (4 menos 6 GHz) e dos futuros sistemas de telefonia móvel 5G (27 menos 29 GHz). Também são apresentados os resultados das simulações e testes realizados em todos os dispositivos desenvolvidos. / [en] This work presents the research, dimensioning and design of microstrip Rotman lens. A new methodology for designs with support of computational tools of electromagnetic simulation is presented. Prototypes are developed on dielectric substrates (relative permittivity equal 10.2) for phased array applications in frequencies of defense systems and radar (4 minus 6 GHz) and of future 5G mobile systems (27 minus 29 GHz). Besides that, the results of the simulations and tests performed in all designed devices are presented.

L’objectif de cette thèse était de concevoir, fabriquer, et tester des transducteurs ultrasonores multi – éléments pour des applications en environnements sévères. Dans ce contexte, des techniques de caractérisation des matériaux ont été développées afin d’adapter la conception des transducteurs en fonction des contraintes de l’environnement, et plus particulièrement la température. Deux types de conceptions ont été étudiées selon les applications visées : La première application consistait à développer un transducteur ultrasonore permettant de réaliser des contrôles non destructifs dans des réacteurs de génération IV (refroidi au sodium liquide) lors d’un arrêt de tranche. Dans ce cas, l’environnement sévère était caractérisé par une température de 200 °C, et la présence de sodium liquide. Des radiations pouvaient également être présentes. Pour cette application, un transducteur (nommé LiNa) sous la forme d’un projecteur ultrasonore linéaire de 20 éléments, fonctionnant à 2.5MHz a été fabriquée, puis testé en eau et en sodium liquide. La seconde application consistait à développer un transducteur ultrasonore permettant de réaliser des contrôles non destructifs en contact de pièces massives en cours de soudage. Une pièce massive est par exemple une cuve de réacteur nucléaire. Ce transducteur permet de détecter des défauts dans une soudure très rapidement après sa réalisation, et ainsi corriger directement cette dernière, sans attendre que les pièces soient refroidies. Pourcette application, un transducteur (nommé MaCo) sous forme de matrice 8 × 8 éléments, fonctionnant à 5MHz a été développé, et caractérisé de la température ambiante, jusqu’à 240 °C. Avec ce capteur, Avec ce capteur, des échos en ondes transversales ont été obtenus jusqu’à la température limite, sans refroidissement. / The goal of this thesis was to design, fabricate and test phased arrays ultrasonic transducers for harshenvironment applications. In this context, characterization methods were developed in order to adapt transducerdesign to the environment. We designed two types of ultrasonic phased array transducers according to theconsidered application:The first application aimed at developping an ultrasonic transducer for non destructive testing in IVth generationnuclear reactors (cooled with liquid sodium) during reactor outages. In this case, the harsh environment wascharacterized by a temperature of 200 °C, and the presence of liquid sodium. Radiations could also be present.For this application, a 20 elements 2.5MHz immersion linear projector (called LiNa) was fabricated then testedunder water and under liquid sodium.The second application aimed at developping an ultrasonic transducer in order to realize non destructive testingin contact with massive pieces during welding. A massive piece for example is a tank for nuclear plant reactor.The transducer will permit to quickly detect defects in a weld after its realization, and then correct it directlyif necessary, without waiting for the pieces to cool down at ambient temperatures. For this application,a 64elements 5MHz matrix transducer (named MaCo) were developed and tested from ambient to 240 °C. Thetransducer worked up to the limit temperature without any cooling system, and some typical defects weredetected.