Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 215-218. / by Leon K. Ekchian. / M.S.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERONAUTICS. / Bibliography: p. 235-239. / by Jere Schenck Meserole, Jr. / Ph.D.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 117-124).

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Gordon L. Stuber; Committee Member: Alfred D. Andrew; Committee Member: John A. Buck; Committee Member: Steven W. McLaughlin; Committee Member: Ye (Geoffrey) Li.

Mémoire (M.Eng.)--Université du Québec à Chicoutimi, 1997. / Document électronique également accessible en format PDF. CaQCU

Thesis (PhD)-Open University. BLDSC no.DX190076.

CNPq / Este trabalho descreve o desenvolvimento de um dispositivo sintonizador de redes de Bragg em fibra óptica que pode ser utilizado como um filtro óptico ou como um sintonizador de canais de comunicação óptica de redes WDM. O dispositivo faz uso de uma peça mecânica que altera o comprimento de onda de Bragg através da compressão da fibra. A peça mecânica é tracionada por um atuador piezoelétrico multicamadas. O dispositivo ainda é composto por um interrogador de redes de Bragg utilizando uma técnica passiva com a utilização de filtro fixo. O filtro fixo utilizado é um cristal com uma camada de filmes finos. O dispositivo é caracterizado utilizando-se duas redes de Bragg e são avaliados os parâmetros dinâmicos do sistema como a resolução em comprimento de onda e velocidade de sintonização. O sistema de interrogação é ainda descrito através do emprego de simulações computacionais e o sistema desenvolvido é comparado com dados obtidos através de simulações. / This work describes the development of a device that can be used as a tunable filter based on a Fiber Bragg Grating or as an optical network switch. The device is made of a mechanical system used to compress the fiber optic in witchi the FGB is inscribed. The mechanical device uses a piezoelectrical multiplayer actuator. The device also contains a passive Fiber Bragg Grating interrogation system using a fixed filter based on a thin film. The device is studied with two FGB and the dynamical characteristics of the systems analyzed, especially the wavelength resolution and the tuning velocity. The device is also investigated using digital simulations and the results are compared with these simulations.

Orientador: Elnatan Chagas Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T07:34:18Z (GMT). No. of bitstreams: 1 Spengler_AndersonWedderhoff_D.pdf: 6948072 bytes, checksum: 5751258b2120091b7b942e5664da4fb2 (MD5) Previous issue date: 2014 / Resumo: São apresentadas neste trabalho novas técnicas de condicionamento e processamento de sinais para girômetros interferométricos a fibra óptica (IFOG) em malha fechada óptica para sistemas de navegação inercial. Uma nova técnica de condicionamento do sinal do girômetro foi desenvolvida com o objetivo de minimização do offset da medida. As técnicas de modulações mais usadas na configuração de malha fechada óptica foram comparadas através de simulações e implementações físicas indicando algumas contribuições para melhoria delas. Uma nova técnica de modulação foi desenvolvida, com quatro níveis e seis fases. Os detalhes da montagem final são mostrados, enfatizando os pontos críticos da implementação, como os filtros utilizados no condicionamento do sinal e os componentes eletrônicos utilizados na geração do sinal de realimentação. Um girômetro foi desenvolvido utilizando a eletrônica apresentada neste trabalho e a parte óptica feita pela Optsensys. Ele apresentou deriva de aproximadamente a 0,01°/h e estabilidade do fator de escala na ordem de 10 ppm, valores compatíveis com girômetros da classe inercial. O angle random walk deste girômetro foi 0,0022°??hr, superior ao indicado para a classe inercial / Abstract: In this work are presented new techniques for signal conditioning and processing for inter-ferometric fiber optic gyrometers (IFOG) with optical closed-loop for inertial navigation systems. A new conditioning technique for the gyro signal was developed in order to reduce the offset. The most commonly used modulation techniques were compared through simulations and im-plementations indicating some improvements. A new modulation technique was developed, with four levels and six phases. Details of the final assembly are shown, emphasizing the critical points of implementation, such as the filters used in signal conditioning and electronic components used in the generation of the feedback signal. A gyro was developed using shown electronics and an optical made by Optsensys. It achieved a bias instability of approximately 0.01 °/ h and scale factor stability on the order of 10 ppm, consistent with the inertial class specifications. The gyro¿s angle random walk was 0.0022 °/?hr, this value is higher than that indicated for the inertial class / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

The objective of this thesis is to study the demodulation of narrowband radio frequency signals by aliasing sampling in order to reduce the sampling rate. The spectrum can be recreated at the lower frequency position by aliasing sampling. However, if the sampling rate is deviated from the desired one, error will occur. The sensitivity to the frequency error of aliasing sampling is studied. One main reason of the deviation of the sampling rate is the frequency drifting of the local oscillator. Being able to compensate the oscillator drifting errors inexpensively, automatic frequency control (AFC) loops are important at receivers. Two major digital AFC algorithms are studied. One is the Phase method AFC, and the other is the Magnitude method AFC. Study indicates that both methods perform almost equally well. One adaptive AFC algorithm is also proposed. The scheme of the adaptive AFC algorithm is to use Upper-bound and Lower-bound techniques to squeeze the frequency errors. It is shown that the adaptive AFC algorithm can achieve up to 20 dB average signal-to-noise power ratio over the Magnitude method AFC under a noisy environment.

Optical fiber magnetometers are extremely sensitive devices which are capable of competing with magnetometers implemented using other technologies. Demodulation of the signals detected using these magnetometers can be performed using either homodyne or heterodyne techniques. Higher sensitivities have been achieved using homodyne rather than heterodyne techniques, but with homodyne demodulation there exists the inherent problem of quadrature-point stabilization. Presented here is a review of existing quadrature-point stabilization methods and experimental results concerning the application of one of them which uses a piezoelectric transducer in the reference arm of an all-fiber Mach-Zehnder interferometer. / Master of Science