This thesis describes the design and measurement of an X-band IQ up/down converter that has been fabricated on a 180nm RF CMOS process. This converter includes components for mixing, frequency doubling, quadrature generation, amplification, and limiting. The specific circuit topologies used include passive double-balanced mixers, RC polyphase filters, and injection locked LC oscillators. The converter is part of a transceiver chain that will make up the dedicated circuitry for each active antenna element of a phased-array radar. An active antenna element combines a radiator with its own transceiver subsystem. A phased-array radar, NetRad, is under development at the University of Massachusetts Amherst and will require thousands of active antenna elements. This motivates the need for low-cost integrated solutions. A silicon-based RF CMOS process provides a low-cost candidate technology to fulfill this requirement.

Text embedding is a widely used method for comparing pieces of text together by mapping them to a compact vector space. One such application is deduplication which consists in finding textual records that refer to the same underlying idea in order to merge them or delete one of them. The current state of the art in this domain uses the Transformer architecture trained on a large corpus of text. In this work, we evaluate the performance of a recently proposed architecture: the Mixer. It offers two key advantages, its parameter count scale linearly with the context window and it is built of simple MLP blocks that benefit from hardware acceleration. We found a 26% increase in performance when using the Mixer compared to the Transformer for a model of similar size. / Textinbäddning är en allmänt använd metod för att jämföra textstycken med varandra genom att mappa dem till ett kompakt vektorutrymme. En sådan tillämpning är deduplicering som består i att hitta textposter som hänvisar till samma underliggande idé för att slå samman dem eller radera en av dem. Den nuvarande tekniken inom detta område använder Transformer-arkitekturen som tränats på en stor textkorpus. I detta arbete utvärderar vi prestandan hos en nyligen föreslagen arkitektur: Mixer. Den erbjuder två viktiga fördelar, dess parameterantal skalar linjärt med kontextfönstret och den är byggd av enkla MLP-block som drar nytta av hårdvaruacceleration. Vi fann en 26% ökning av prestanda när vi använde Mixer jämfört med Transformer för en modell av liknande storlek.

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The FCC allocated the spectrum of 402-405 MHz for MICS (Medical Implant Communication Services) applications in 1999. The regulations for MICS band apply to devices that support the diagnostic and/or therapeutic functions associated with implanted medical electronics. The implanted devices aid organs and control body functions of patients to support specific treatments, and monitor patients continuously so that necessary action can be taken in advance to avoid serious conditions. To enable to use MICS applications, several requirements must be satisfied. An implanted wireless device should have a small size, consume ultra-low power, and achieve the date rate of at least 200 kbps within 2 m distance. The major challenge is to realize ultra-low power devices. Thus the low-power design of the RF circuit is crucial for MICS applications as the power consumption of the wireless devices is mostly contributed by RF circuits. This thesis investigates low-power design of an LNA and a down-conversion mixer of a receiver for MICS applications. The key idea is to stack an LNA and a mixer, while the LNA operates in the normal super-threshold region and the mixer in the sub-threshold region. In addition, a gm-boosting technique with a capacitor cross-coupled at the LNA input stage is also adopted to achieve a low noise figure (NF) and high linearity, which is critical to the overall performance of the receiver. The mixer operating in the sub-threshold region significantly reduces power dissipation and relaxes the voltage headroom without sacrificing the LNA performance. The relaxed voltage headroom enables stack of the LNA and the mixer with a low supply voltage of 1.2 V. The proposed circuit is designed in 0.18 μm RF CMOS technology. The merged LNA and mixer consumes only 1.83 mW, and achieves 21.6 dB power gain. The NF of the block is 3.55 dB at 1 MHz IF, and the IIP3 is -6.08 dBm. / Master of Science

Superparamagnetic nanoparticles have potential applications in targeted drug delivery and as magnetic resonance imaging contrast agents. Magnetite clusters are of particular interest for these applications because they provide higher magnetic flux (under a magnetic field) than individual magnetite nanoparticles, are biocompatible, and their size and compositions can be controlled. This thesis involves the controlled synthesis and characterization of clusters composed of magnetite nanoparticles stabilized with an amphiphilic block copolymer. It outlines a method to design and form well-defined and colloidally stable magnetite clusters. A Multi Inlet Vortex mixer (MIVM) was used because it is a continuous process that yields particles with relatively narrow and controlled size distributions. In the MIVM, four liquid streams collide under turbulent conditions in the mixing chamber where clusters form within milliseconds. The formation of magnetite clusters was studied in the presence of amphiphilic block copolymers containing poly (ethylene oxide) to provide steric stabilization and control of size distributions using flash nanoprecipitation. First, the mixer was tested using β-carotene as a model compound to form nanoparticles stabilized with an amphiphilic triblock copolymer poly(propylene oxide)-b-poly(ethylene oxide) (F127) at different Reynolds numbers and supersaturation values. Size analysis was done using dynamic light scattering and nanoparticle tracking analysis techniques. The cluster structure was studied using electron microscopy and magnetite compositions were measured using thermogravimetric analysis. Finally, the stability of magnetite clusters was studied over time and the effect of an applied magnetite field on the colloidal stability was investigated. / Master of Science

The complexity of vehicular communication and radar sensing becomes increasingly complex with the growing demand for advanced driver-assistant systems in the automotive industry. Researchers are currently looking into combining communication and sensing by utilizing traditional communication waveforms in the mmWave radar bands to mitigate congestion and inter-radar interference. This thesis investigates a local-oscillator (LO) phase-shifting architecture to simplify the implementation of D-band (110–170 GHz) phased arrays for such applications. The constructed signal chain includes four 8–12-GHz voltage-controlled analog phase shifters, each mounted on the LO feed of a quadrature subharmonic upconverter, and a four-channel slot antenna. Through careful calibration of the analog control voltages, the 100-MHz baseband feed, and the LO distribution, antenna measurements in an anechoic chamber resulted in a beambook with antenna diagrams at seven angles from −30° to +30°. The gain was between 10.78 dB and 12.80 dB relative to the gain of one element, and the sidelobe levels were less than 8.9 dB. / Fordononsindustrins ökade efterfrågan på avancerade assistansystem gör framtidens kommunikation och radaravkänning allt mer komplex. Forskare undersöker just nu möjligheten att integrera kommunikation och radar genom att använda traditionella vågformer på millimetervågsfrekvenser för att förhindra nätverksträngsel och interferens mellan närliggande sensorer. Detta examensarbete undersöker möjligheten att fasstyra en radarantenn genom att skifta fasen på sändarens lokaloscillator (LO) och på så sätt förenkla konstruktionen av fasade gruppantenner på D-bandet (110–170 GHz). Signalkedjan bestod av fyra spänningsstyrda 8–12 GHz-fasskiftare, var och en monterade på LO-matningen till en subharmonisk mixer, samt en fyrkanals slitsantenn. Genom noggrann kalibrering av kontrollspänningar, 100 MHz-basbandsmatning och LO-distribution kunde antennmätningar i en ekofri kammare påvisa de önskade antenndiagramen för sju vinklar mellan −30° och +30°. Förstärkningen i förhållande till ett antennelement var mellan 10.78 dB och 12.80 dB och sidlobsnivåerna var lägre än 8.9 dB.

La mesure de distance et la détection d'objets sont devenues essentielles dans de nombreux domaines tels que l'automobile ou la robotique, les applications médicales, les procédés industriels et agricoles, les systèmes de surveillance et de sécurité, etc. Dans le but d'améliorer les performances des dispositifs de télémétrie laser en terme de bruit et de diaphonie, une technique hétérodyne par mélange optoélectronique doit être utilisée. Par ailleurs, l'aspect système embarqué nécessite une réduction de l'encombrement et de la consommation à performances égales. L'intégration de mélangeurs optoélectroniques en technologie CMOS apporte donc une solution optimale à cette approche grâce à ses multiples avantages (intégration du circuit d'instrumentation sur la même puce, modèles bien connus, coût raisonnable, performances élevées,…). Ainsi cette thèse traitera de l'étude de mélangeurs optoélectroniques en technologie CMOS pour la télémétrie embarquée haute résolution. Le premier chapitre de ce manuscrit présente les diverses technique de mesure de distance par télémétrie laser par et justifie le choix de la télémétrie laser par déphasage ainsi que le gain en performances lié à l'hétérodynage. Le second chapitre décrit les mélangeurs électriques et optoélectroniques ainsi que les propriétés nécessaires à leur réalisation. Quelques photodétecteurs y sont présentés au vu de la possibilité de les utiliser en mélangeurs optoélectroniques et d'une intégration potentielle en technologie CMOS. Les principales contraintes liées à l'intégration en technologie CMOS de photocapteurs utilisables en mélangeurs optoélectroniques, sont exposés dans la troisième partie. Les travaux de conception et d'optimisation des structures ainsi que les phases de simulations et de test y sont détaillés. Enfin, pour valider expérimentalement les études précédentes, le dernier chapitre présente la conception d'une chaîne de mesure multivoies pour une tête de photoréception CMOS matricée pour un télémètre laser embarqué haute résolution. / Distance measurement and object detection has become essential in many fields such as automotive and robotics, medical applications, industrial processes and farming systems, surveillance and security, etc.. In order to improve the performance of laser ranging devices in terms of noise and crosstalk, an optoelectronic heterodyne technique of mixing should be used. Moreover, the aspect of embedded system requires a reduction in the size and power consumption for the same performance. The integration of optoelectronic mixers in CMOS technology will provide an optimal solution to this approach through its many advantages (integrated instrumentation circuit on the same chip, well-known models, reasonable cost, high performance, ...). Thus this thesis will focus on the study of optoelectronic mixers in CMOS technology for high resolution, embedded laser range finding systems. The first chapter of this thesis discusses the various technique of distance measurement by laser ranging and justifies the choice of phase shift technique and the gain in performance related to heterodyning. The second chapter describes the electrical and optoelectronic mixers and the properties needed to develop them. Some photodetectors are presented given the opportunity to use optoelectronic mixers and a potential integration with CMOS technology. The main constraints to the integration of CMOS photosensors used in optoelectronic mixers are set out in Part III. The work of design and optimization of structures and phases of simulations and testing are detailed. Finally, to experimentally confirm the earlier studies, the final chapter presents the design of a measuring head for a multichannel photoreceptor CMOS for a high resolution laser range finder.

<p>Kvalitetno me&scaron;anje pra&scaron;kastih materijala, čestica ili granula je od izuzetnog inženjerskog, energetskog, ekonomskog i ekolo&scaron;kog značaja u raznim granama industrije: prehrambenoj, procesnoj, hemijskoj, farmaceutskoj industriji. Efikasnost me&scaron;anja, dizajn opreme i parametri procesa me&scaron;anja imaju značajan uticaj na kvalitet i cenu poluproizvoda ili finalnog proizvoda.<br />U ovoj tezi, prikazana je upotreba metode diskretnih elemenata (DEM) na modelovanje me&scaron;anja granula i/ili pra&scaron;kastih materijala (granulisani zeolit ili kukuruzna prekrupa) u različitim konfiguracijama statičkih me&scaron;ača Komax i Ross, kao i za modifikovane pužne transportere / predme&scaron;alice. Primenjen je i metod računske dinamike fluida (CFD) za modelovanje protoka fluida u Ojlerovom vi&scaron;efaznom modelu, za predviđanje pona&scaron;anja čestica unutar različitih konfiguracija statičkih me&scaron;alica.<br />Ispitivano je petnaest horizontalnih pužnih transportera sa nepromenljivog koraka, sa modifikovanom geometrijom, različitih dužina pužnice, sa dodatnim elementima na pužnoj spirali, radi istraživanja mogućnosti me&scaron;anja granulisanog materijala, tokom transporta materijala (granulisani zeolit).<br />Rezultati matematičkog modeliranja i numeričke simulacije su upoređeni sa odgovarajućim eksperimentalnim rezultatima na osnovu stepena pome&scaron;anosti me&scaron;avine, primenom kriterijuma relativne standardne devijacije (RSD). Zahvaljujući ovde postavljenim modelima moguće je uraditi optimizaciju geometrije i parametara sistema me&scaron;anja uzimajući u obzir kvalitet procesa me&scaron;anja i cenu finalnog proizvoda.</p> / <p>The quality mixing of powders, particles and/or granules obtain an engineering, energetic, economic and ecological importance of various technologies, food industry, pharmaceutical and chemical industry. The mixing efficiency, the design of equipment and mixing parameters exert a strong impact on quality and the price of intermediate or final product. In this thesis, the use of Discrete Element Method (DEM) is shown for modeling of granular and/or powder flow in various multiple Komax and Ross mixing applications, as well as for the modified screw conveyors premixers . Computational Fluid Dynamic (CFD) method was used for modeling of fluid flow through Eulerian multiphase model, for the prediction of particle displacement within the various static mixers configurations. Fifteen horizontal screw conveyors with invariant pitch, with modified geometry and different screw length , with some additional elements welded on the helix were tested for the possibility of granular material mixing during the material transport (granulated zeolite).<br />The results of the numerical simulation are compared with appropriate experimental results, according to relative standard deviation criterion (RSD). Application of this model provide the optimization of the geometry and parameters of mixing systems taking into account the quality of the mixing process and the cost of the final product.</p>