Made available in DSpace on 2017-07-21T19:26:11Z (GMT). No. of bitstreams: 1 Robson Conrado Bonetti.pdf: 15626603 bytes, checksum: 231dca9967dd4955a30038499164faa9 (MD5) Previous issue date: 2014-10-20 / We focus on the study of Colpitts oscillators. We have chosen this circuit due to the fact that it can be useful in applications to communication systems, as well as, it exhibits a rich dynamical behaviour for certain parameter values. In the Colpitts oscillator the operation frequency can vary from few Hertz up to the microwave frequency range, a characteristic that enables the use of this circuit to transmit information in channels with diferent frequency bandwidths. This thesis has two parts: (i) super persistent transient in a master-slave configuration with Colpitts oscillators, and (ii) short-time memories in coupled Colpitts. We considered Colpitts oscillators coupled according to a master-slave configuration to study chaos synchronisation. We revealed the existence of super persistent transients in this coupled system. Moreover, we showed that an additive noise in the slave system may suppress chaos synchronisation. When synchronisation is not suppressed, the noise induces longer transients. Moreover, we considered a network of coupled circuits, Colpitts oscillators, and we investigated memory storage with an external input. The memories were defined in terms of the diferences among the electrical currents amplitudes. We showed the existence of multiple memories, which enables us to use these systems to encode signals. / Concentramos o estudo nos osciladores Colpitts. Escolhemos este circuito devido ao fato de que ele pode ser útil em aplicações para sistemas de comunicação, bem como, exibe um rico comportamento dinâmico em certos valores de parâmetros. No oscilador Colpitts, a frequência de operação é de variar de alguns Hertz até a faixa de frequências de microondas, característica esta que permite a utilização deste circuito para transmitir informações em canais com diferentes larguras de banda de frequência. Esta tese tem duas partes:(i) transiente superpersistente em osciladores Colpitts numa configuração mestre-escravo; (ii) memórias de curta duração em Colpitts acoplados. Consideramos osciladores Colpitts acoplados de acordo com uma configuração mestre-escravo para estudar a sincronização de caos. Revelamos a existência de transientes superpersistentes neste sistema acoplado. Além disso, mostramos que um ruído aditivo no sistema escravo pode suprimir a sincronização caótica. Quando a sincronização é suprimida, o ruído induz transientes mais longos. Além disso, considerou-se uma rede de circuitos acoplados, osciladores Colpitts, e investigamos o armazenamento de memória com uma entrada externa. As memórias foram definidas em termos das diferenças entre as amplitudes das correntes elétricas. Mostramos a existência de múltiplas memórias, o que nos permite utilizar estes sistemas para codificar sinais.

Manufacturers of cast metal parts are interested in the development of a feedback control system for use with the Precision Sand-Casting (PSC) process. As industry demands the ability to cast more complex geometries, there are a variety of challenges that engineers have to address. Certain characteristics of the mold, such as thick-to-thin transitions, extensive horizontal or flat surfaces, and sharp corners increase the likelihood of generating defective casts due to the turbulent metal-flow during fills. Consequently, it is critical that turbulent flow behavior within the mold be minimized as much as possible. One way to enhance the quality of the fill process is to adjust the flow rate of the molten metal as it fills these critical regions of the mold. Existing systems attempt to predict the position of the metal level based on elapsed time from the beginning of the fill stage. Unfortunately, variability in several aspects of the fill process makes it very difficult to consistently predict the position of the metal front. A better approach would be to embed a sensor that can detect the melt through a lift-off distance and determine the position of the metal-front. The information from this sensor can then be used to adjust the flow rate of the aluminum as the mold is filled. This thesis presents the design of a novel non-invasive sensor monitoring system. When deployed on the factory floor, the sensing system will provide all necessary information to allow process engineers to adjust the metal flow-rate within the mold and thereby reduce the amount of scrap being produced. Moreover, the system will exhibit additional value in the research and development of future mold designs.

Ο ταλαντωτής αποτελεί σημαντικό κομμάτι κάθε τηλεπικοινωνιακού συστήματος. Το σημαντικότερο στοιχείο της απόδοσής του είναι ο θόρυβος φάσης. Για τη βελτίωσή του χρησιμοποιείται η μέθοδος του injection locking. Με αυτή τη μέθοδο ένα σήμα αναφοράς με καλά χαρακτηριστικά θορύβου χρησιμοποιείται για να βελτιώσει την έξοδο του ταλαντωτή. Χρησιμοποιείται μια τοπολογία τροποποιημένου ταλαντωτή Colpitts, ο οποίος εξομοιώνεται και υλοποιείται. Με τις μετρήσεις που ακολουθούν επιβεβαιώνεται η καλύτερη συμπεριφορά θορύβου που επιτυγχάνει η μέθοδος του injection locking. / Oscillators form an integral part of all communication systems. Their most crucial element regarding performance is phase noise. To improve it we use the method of injection locking. With this method, a reference signal with good noise characteristics is used to improve the output of the oscillator. A modified Colpitts oscillator topology is used which is both simulated and implemented as a circuit board. Measurements confirmed that injection locking improved the characteristics of phase noise.

This thesis focuses on the design and analysis of a novel variable inductor (VID) based VCO solution to the frequency tuning range (TR) limitation of the IEEE 802.11ad compliant radio systems. The IEEE 802.11ad standard has drawn strong attention from the industry as the next generation affordable multi-gigabit speed wireless communication standard. Prepared for the global market, IEEE 802.11ad compliant systems are required to cover a broad 8 GHz TR centered on 60 GHz. This wide TR at V band imposes significant challenge to the VCO design in radio transceivers, and makes the TR of the integrated VCO a major bottleneck to the successful commercialization of many IEEE 802.11ad compliant radio systems today. As an effort to solve the current TR problem for the IEEE 802.11ad compliant radio systems, 2 VCOs designs based on this novel VID-based solution and a conventional Colpitts-Clapp VCO design are presented in this thesis report. The novel VCOs integrate a VID into the differential Colpitts configuration to create a feasible solution to the aforementioned TR problem. The VID in the VCO tank eliminates the base node varactors and their fixed parasitic capacitance that degrades TR in conventional VCO designs, while the differential Colpitts configuration provides advantageous performance at mm-wave frequencies and high output power for real-world applications. Also, a fundamental 30 GHz Colpitts-Clapp VCO was developed in conjunction with the other 2 VCOs for comparison purposes. One of the 2 VID-based VCO designs is a fundamental 30 GHz VID-based Colpitts VCO that covers 17% TR for proof of concept to the novel topology. Another is an IEEE 802.11ad compliant 60 GHz VCO chain consists of the 30 GHz VID-based Colpitts VCO and a frequency doubler covering 17% TR with 3 dBm output power and -115.7 dBc/Hz phase noise at 10 MHz offset. The conventional Colpitts-Clapp VCO is used to compare with the other 2 VID-based VCOs. As the measurement results indicate, this VID-based VCO topology provides a viable solution to overcome the TR bottleneck in the current IEEE 802.11ad compliant VCO development. All 3 VCOs are fabricated using a 130 nm SiGe BiCMOS process. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-01-23 13:40:31.258

Le besoin croissant de réduction du volume, de la masse et de la consommation des dispositifs électroniques sans pertes deperformances concerne aussi les oscillateurs à quartz utilisés dans les applications métrologiques (bases de temps, capteurs),la téléphonie, la navigation... Dans le cadre de cette problématique, nous avons développé un ASIC (Application SpecificIntegrated Circuit) en technologie 0,35 μm SiGe BiCMOS (Austriamicrosystems®) fonctionnant sous 3,3 V (±10%) pourréaliser un oscillateur à quartz miniature opérationnel sur une gamme en fréquence allant de 10 MHz à 100 MHz. Ce circuitdont la surface ne dépasse pas les 4 mm2 est composé de diverses cellules RF, depuis le système d’entretien de type Colpitts,la mise en forme et jusqu’à l’adaptation du signal à sa charge d’utilisation (50 W ou HCMOS). Ces cellules sont toutespolarisées par une référence de tension interne de type bandgap CMOS. La consommation totale du circuit en charge resteinférieure à 100 mW pour un bruit blanc de phase visé de −150 dBc/Hz à 40 MHz. Pour minimiser la sensibilité thermiquedu résonateur et ainsi pouvoir s’orienter également vers des applications OCXO (Oven Controlled Crystal Oscillator),nous avons partiellement intégré une régulation de température dans notre ASIC. Cette régulation fortement dépendante del’architecture thermo-mécanique a été dimensionnée puis validée au travers de modélisations par analogie sous Spectre®.Notre électronique intégrée nécessite peu de composants externes et nous l’avons reportée par flip chip sur une interfacespécifique pour / The increasing demand for high-performance devices featuring compact, lighter-weight designs with low-power consumptionalso impacts quartz crystal oscillators used in metrological applications (time bases, sensors), telephony or navigation. Inthis context, we have developed an ASIC (Application Specific Integrated Circuit) in 0.35 μm SiGe BiCMOS technology(Austriamicrosystems®) supplied by 3.3 V (±10%) to realize a miniaturized quartz crystal oscillator operating in the 10 MHzto 100 MHz frequency range. The fabricated die hosts several RF cells in a 4 mm2 area, including a sustaining amplifier(Colpitts topology), a signal shaping circuit and an output buffer dedicated to a specific load (50 W or HCMOS). These cellsare biased by a fully integrated CMOS bandgap voltage reference. The die power consumption remains lower than 100 mWfor a targeted phase noise floor as low as −150 dBc/Hz at a 40 MHz carrier frequency. A thermal control loop has in additionbeen partially integrated to the ASIC, in order to reduce the quartz resonator thermal sensitivity as well as to extend thepotential application field of the developed die to oven applications (OCXO). The thermal control, that is strongly dependanton the mechanical design, has been designed and tested by using electrical analogy modeling on Spectre® simulator. Finallyour integrated circuit has been connected to a specific substrate using flip chip technology to realize a miniaturized quartzcrystal oscillator packaged on a TO-8 enclosure (Ø15.2 mm).

Le besoin croissant de réduction du volume, de la masse et de la consommation des dispositifs électroniques sans pertes deperformances concerne aussi les oscillateurs à quartz utilisés dans les applications métrologiques (bases de temps, capteurs),la téléphonie, la navigation... Dans le cadre de cette problématique, nous avons développé un ASIC (Application SpecificIntegrated Circuit) en technologie 0,35 μm SiGe BiCMOS (Austriamicrosystems®) fonctionnant sous 3,3 V (±10%) pourréaliser un oscillateur à quartz miniature opérationnel sur une gamme en fréquence allant de 10 MHz à 100 MHz. Ce circuitdont la surface ne dépasse pas les 4 mm2 est composé de diverses cellules RF, depuis le système d'entretien de type Colpitts,la mise en forme et jusqu'à l'adaptation du signal à sa charge d'utilisation (50 W ou HCMOS). Ces cellules sont toutespolarisées par une référence de tension interne de type bandgap CMOS. La consommation totale du circuit en charge resteinférieure à 100 mW pour un bruit blanc de phase visé de −150 dBc/Hz à 40 MHz. Pour minimiser la sensibilité thermiquedu résonateur et ainsi pouvoir s'orienter également vers des applications OCXO (Oven Controlled Crystal Oscillator),nous avons partiellement intégré une régulation de température dans notre ASIC. Cette régulation fortement dépendante del'architecture thermo-mécanique a été dimensionnée puis validée au travers de modélisations par analogie sous Spectre®.Notre électronique intégrée nécessite peu de composants externes et nous l'avons reportée par flip chip sur une interfacespécifique pour

This report describes the design and implementation of a prototype for an amplitude modulated laser rangefinder, which is made on a PCB consisting of a laser module emitting light, a photodiode receiving the light reflected from the target, and other components. The design is made for the different power levels, generation of the modulation output and the reception of the signal. The sinusoidal wave is generated with an oscillator circuit and filtered out to produce a pure sine signal. The system requires different voltage levels and current values, which is done with DC-DC converters. Finally, a receiver circuit is implemented to detect the modulation, which needs a device that transfers light energy into voltage. Many tests have been made to optimize the analog circuit for a stable output. The prototype was created as a PCB design with a laser module and a photodiode mounted on it. In the end, satisfactory results were obtained up to the receiving part, however, the prototype was tested with an external circuit for light detection. There is considerable room for improvement, e.g., signal sampling, working receiver and use of standard voltage levels, but this thesis intends to provide a basis for future work.

Les travaux de recherche présentés dans cette thèse consistent principalement en la conception de fonctions intégrées radiofréquences BiCMOS SiGe exploitant des résonateurs à ondes acoustiques de volume FBAR. Contrairement aux techniques actuelles rencontrées dans l'industrie qui consistent à réaliser des filtres et des résonateurs discrets et à les associer par la suite avec les circuits actifs des émetteurs-récepteurs au niveau du boîtier, nos résonateurs sont directement réalisés sur le substrat silicium des circuits actifs RF par une technique appelée intégration " above-IC ". Avec cette méthode d'intégration, les parasites et la modélisation associés aux microsoudures (Wire Bonding) sont éliminés. Elle permet aussi de se passer des circuits d'interface et d'adaptation nécessaires dans le cas de filtres RF discrets. Ceci permet de réduire considérablement la consommation et le volume des systèmes. Des amplificateurs faible bruit filtrants et des oscillateurs visant le standard WLAN IEEE 802.11a ont ainsi été implantés en utilisant cette technique d'intégration "above IC". Les circuits obtenus sont très compacts, et leurs performances, notamment celles des oscillateurs, sont à l'état de l'art. Par ailleurs, des amplificateurs faible bruit et des VCO LC SiGe intégrés pour application WLAN 5GHz sont également présentés et leurs techniques d'optimisation sont données.