Este trabalho apresenta o projeto de uma portadora que opera na frequência de 8.300 MHz para ser utilizado em moduladores vetoriais diretos com aplicação em sistemas embarcados de satélites. Foram realizados estudos sistêmicos de arquiteturas que operam nesta faixa de frequência com as características necessárias para atender as especificações da European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation da agência espacial europeia -ESA, que regulamenta as frequências e características para sistemas de transmissão para enlace de descida. A partir dos conhecimentos adquiridos nos estudos, é apresentada uma metodologia de projeto visando o atendimento das especificações definidas pela ECSS e a escolha de uma topologia de projeto. Foram realizadas simulações a nível sistêmico, utilizando o software Advanced Design System-ADS da fabricante Keysight Technologies, para definir as especificações de projeto dos circuitos que compõem o sistema de geração da portadora na banda X. O circuito da malha de sincronismo de fase - PLL opera na frequência de 2.075 MHz, onde seu sinal é amplificado e filtrado pela cadeia de amplificação na banda S cuja função é aumentar a isolação para minimizar os efeitos de pulling do oscilador controlado por tensão - VCO, devido à alta velocidade nas transições de tempo de subida e de descida dos sinais digitais I e Q. O filtro também é responsável por aumentar a rejeição de espúrios e harmônicos gerados pelos efeitos não lineares dos amplificadores. O sinal é enviado ao circuito multiplicador de frequências que gera o sinal na banda X e é filtrado por um filtro passa-faixas de linhas acopladas, rejeitando os sinais espúrios provenientes da saída do multiplicador de frequência. Na saída, o sinal passa por uma cadeia de amplificação na banda X para adequar o nível de potência à entrada dos moduladores vetoriais. Os circuitos projetados foram desenvolvidos utilizando tecnologia de microfita de linha. Os protótipos foram caracterizados, apresentando boa concordância com os resultados simulados, comprovando experimentalmente a metodologia de projeto utilizada neste trabalho assim como o atendimento das especificações sugeridas pela ECSS. / This work presents the project of an carrier that works in the frequency of 8,300 MHz to be used in direct vector modulator for embedded system application in satellites. It were realized system level studies of PLL topologies that work in this frequency range with the necessary features to provide the requirements from European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation of the European Space Agency - ESA, which is responsible for the frequencies and features regulation for downlink transmission system. With the knowledge acquired from the studies, it is presented a project method intending to the meet the requirements defined by the ECSS and the definition of a topology to the project. It were performed system level simulation, using the Advanced Design System - ADS tool, from Keysight Technologies, in order to define the design specifications in the project of the circuits of the X band carrier generator developed. The PLL circuit works in the frequency of 2,075 MHz, in which its signal is amplified and filtered for amplifier chain in S band, increasing the isolation to reduce the pulling effects in the voltage controlled oscillator, due to the high-speed transitions in the rise time and fall time of the digital signal I and Q. The filter is also responsible for increasing the rejection of spurious and harmonics generated by non-linear amplifiers effects. The signal is conducted to the frequency multiplier circuit that generates the X band signal and it is filtered by a coupled line bandpass filter, rejecting the spurious from the frequency multiplier output. At the output stage, the signal passes through a X band amplification chain in order to adequate the power level of the vector modulators input level. The specified circuits were designed and developed using microstrip line technology. The prototypes were characterized, presenting adequate results according to the data obtained by the simulations, experimentally reinforcing the project method used in this work as well as the meeting of the requirements suggested by the ECSS.

Este trabalho apresenta o projeto de uma portadora que opera na frequência de 8.300 MHz para ser utilizado em moduladores vetoriais diretos com aplicação em sistemas embarcados de satélites. Foram realizados estudos sistêmicos de arquiteturas que operam nesta faixa de frequência com as características necessárias para atender as especificações da European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation da agência espacial europeia -ESA, que regulamenta as frequências e características para sistemas de transmissão para enlace de descida. A partir dos conhecimentos adquiridos nos estudos, é apresentada uma metodologia de projeto visando o atendimento das especificações definidas pela ECSS e a escolha de uma topologia de projeto. Foram realizadas simulações a nível sistêmico, utilizando o software Advanced Design System-ADS da fabricante Keysight Technologies, para definir as especificações de projeto dos circuitos que compõem o sistema de geração da portadora na banda X. O circuito da malha de sincronismo de fase - PLL opera na frequência de 2.075 MHz, onde seu sinal é amplificado e filtrado pela cadeia de amplificação na banda S cuja função é aumentar a isolação para minimizar os efeitos de pulling do oscilador controlado por tensão - VCO, devido à alta velocidade nas transições de tempo de subida e de descida dos sinais digitais I e Q. O filtro também é responsável por aumentar a rejeição de espúrios e harmônicos gerados pelos efeitos não lineares dos amplificadores. O sinal é enviado ao circuito multiplicador de frequências que gera o sinal na banda X e é filtrado por um filtro passa-faixas de linhas acopladas, rejeitando os sinais espúrios provenientes da saída do multiplicador de frequência. Na saída, o sinal passa por uma cadeia de amplificação na banda X para adequar o nível de potência à entrada dos moduladores vetoriais. Os circuitos projetados foram desenvolvidos utilizando tecnologia de microfita de linha. Os protótipos foram caracterizados, apresentando boa concordância com os resultados simulados, comprovando experimentalmente a metodologia de projeto utilizada neste trabalho assim como o atendimento das especificações sugeridas pela ECSS. / This work presents the project of an carrier that works in the frequency of 8,300 MHz to be used in direct vector modulator for embedded system application in satellites. It were realized system level studies of PLL topologies that work in this frequency range with the necessary features to provide the requirements from European Cooperation for Space Standardization, ECSS - Space Engineering Radio Frequency and Modulation of the European Space Agency - ESA, which is responsible for the frequencies and features regulation for downlink transmission system. With the knowledge acquired from the studies, it is presented a project method intending to the meet the requirements defined by the ECSS and the definition of a topology to the project. It were performed system level simulation, using the Advanced Design System - ADS tool, from Keysight Technologies, in order to define the design specifications in the project of the circuits of the X band carrier generator developed. The PLL circuit works in the frequency of 2,075 MHz, in which its signal is amplified and filtered for amplifier chain in S band, increasing the isolation to reduce the pulling effects in the voltage controlled oscillator, due to the high-speed transitions in the rise time and fall time of the digital signal I and Q. The filter is also responsible for increasing the rejection of spurious and harmonics generated by non-linear amplifiers effects. The signal is conducted to the frequency multiplier circuit that generates the X band signal and it is filtered by a coupled line bandpass filter, rejecting the spurious from the frequency multiplier output. At the output stage, the signal passes through a X band amplification chain in order to adequate the power level of the vector modulators input level. The specified circuits were designed and developed using microstrip line technology. The prototypes were characterized, presenting adequate results according to the data obtained by the simulations, experimentally reinforcing the project method used in this work as well as the meeting of the requirements suggested by the ECSS.

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This thesis deals with optical synthesis of unmodulated and modulated microwave signals. Generation of microwave signals based on optical heterodyning is discussed in detail. The effect of phase noise of laser on heterodyned output has been studied for different phase noise profiles. Towards this, we propose a generic algorithm to numerically model the linewidth broadening of a laser due to phase noise. Generation of microwave signals is demonstrated practically by conducting an optical heterodyning experiment. Signals ranging in frequency from 12.5 MHz to 27 GHz have been generated. Limitations of optical heterodyning based approach in terms of phase noise performance and frequency stability are discussed and practically demonstrated. A hardware-efficient Optical Phase Locked Loop (OPLL) is proposed to overcome these issues. Phase noise tracking performance of the proposed OPLL has been experimentally demonstrated. Phase noise values as low as -105 dBc/Hz at 10 KHz offset have been achieved. Optical modulators, owing to their extremely low electro-optic response time, can support high frequency modulating signals. This makes them highly attractive in comparison to their microwave counterparts. In this thesis, we propose techniques to generate microwave signals modulated at very high bit rates by down-converting the corresponding modulated optical signals to microwave domain. Down-conversion required for this process is achieved by optical heterodyning. The proposed concept has been theoretically analyzed, simulated and experimentally validated. Amplitude Modulated and ASK modulated microwave signals have been generated as Proof-of-Concept. Limitations posed by OPLL in generation of angle modulated microwave signals by optical heterodyning have been brought out. Schemes overcoming these limitations have been proposed towards generation of BPSK and QPSK modulated microwave signals. Integrated Optics (IO) technology has been studied as a means of implementation of the proposed concepts. IO components like Sinusoidal bends, Y-branch splitters and Electro-Optic-Modulators (EOMs) have been designed towards optical synthesis of modulated microwave signals. Propagation of modulated optical signal through these IO components has also been studied. An all-optic scheme based on Optical Beam Forming is proposed for transmission of QPSK modulated signal. Limitation of phase-shifting based approach, in terms of beam-squint, has been brought out. True-Time-Delay based approach has been proposed for applications demanding wide instantaneous bandwidth to avoid beam-squint. Algorithms / numerical methods required for analyses and simulations associated with the above-mentioned tasks have been evolved. This study is envisaged to provide useful insight into the realization of high-speed, compact, light-weight data transmitting systems based on Integrated Optics for future onboard spacecraft applications. This work, we believe, is a step towards realization of an Integrated Optic System-on-Chip solution for specific microwave data transmission applications.

L'objectif de cette thèse est de proposer l'approche la plus appropriée afin de minimiser le coût d'intégration de petite éolienne dans un micro-réseau DC urbain. Une petit éolienne basé sur un machine synchrone à aimant permanent (MSAP) est considéré à étudier. Un état de l'art concernant les énergies renouvelables, micro-réseau DC, et la production d'énergie éolienne, est fait. Comme le capteur mécanique de cette structure est relativement d'un coût élevé, les différents types de contrôle pour un système de conversion éolienne sont présentés afin de choisir une structure active de conversion d'énergie et un MSAP sans capteur. Par conséquent, un estimateur de vitesse/position est nécessaire pour contrôler le système. Ainsi, les méthodes différentes proposées dans la littérature sont considérées et classifiées à étudier dans les détails, puis les plus efficaces et largement utilisés sont à vérifier dans la simulation et expérimentalement pour le système étudié. Les méthodes choisies sont: estimation de la flux de rotor avec boucle à verrouillage de phase (PLL), observateur à mode glissement (SMO), observateur de Luenberger d'ordre réduit, et filtre de Kalman étendu (EKF). Face à d'autres méthodes, l'estimateur basé sur un modèle EKF permet une commande sans capteur dans une large plage de vitesse et estime la vitesse de rotation avec une réponse rapide. Le réglage des paramètres EKF est le problème principal à sa mise en œuvre. Par conséquent, pour résoudre ce problème, la thèse présente une méthode adaptative, à savoir réglage-adaptatif d’EKF. En conséquence, et grâce à cette approche, le coût total du système de conversion est réduite et la performance est garantie et optimisée. / The aim of this thesis is to propose the most appropriate approach in order to minimize the cost of integration of a wind generator into a DC urban microgrid. A small-scale wind generator based on a permanent magnet synchronous machine (PMSM) is considered to be studied. A state of the art concerning the renewable energies, DC microgrid, and wind power generation is done. As the mechanical sensor for this structure is relatively of high cost, various types of wind conversion system control are presented in order to choose an energy conversion active structure and a sensorless PMSM. Therefore, a speed/position estimator is required to control the system. Thus, different methods proposed in literatures are considered and classified to be studied in details, and then the most effective and widely used ones are to be verified in simulation and experimentally for the studied system. The methods which are chosen are: rotor flux estimation with phase locked loop (PLL), sliding mode observer (SMO), Luenberger observer of reduced order, and extended Kalman filter (EKF). Facing to other methods, the EKF model-based estimator allows sensorless drive control in a wide speed range and estimates the rotation speed with a rapid response. The EKF parameters tuning is the main problem to its implementation. Hence, to solve this problem, the thesis introduces an adaptive method, i.e. adaptive-tuning EKF. As a result and grace to this approach, the total cost of conversion system is reduced and the performance is guaranteed and optimized.