Demodulation Technique
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Ultrasonic method of microvibration detection: part II - additional processing method and applications
Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used fo
Res. Biomed. Eng.. Publicado em: 17/08/2017
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2. New technique for the implementation of digital demodulation of fiber optic gyroscopes / Implementação de uma nova tecnica para demodulação digital de sinal de giroscopio a fibra optica
Gyroscopes are devices used to measure angular orientation, being extensively employed for guidance, navigation and stabilization. Among the many types of gyroscopes, IFOG (Interferometer Fiber Optic Gyroscope), based on Sagnac effect, is the most interesting solution due to its high sensitivity, resolution, reliability, small size and EMI immunity. The pres
Publicado em: 2009
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3. ANÁLISE DA CALIBRAÇÃO DE SENSORES A REDE DE BRAGG EM FIBRAS ÓPTICAS INTERROGADOS ATRAVÉS DA TÉCNICA DE FILTROS FIXOS / ANALYSIS OF THE CALIBRATION TO BRAGG GRATING SENSORS IN FIBER OPTICS INTERROGATED TROUGHT FIXED FILTERS TECHNIQUE
Nesse trabalho, descreve-se o desenvolvimento de uma calibração do sistema de interrogação dos espectros das redes de Bragg baseando-se em uma simulação numérica adotada de testes experimentais. O objetivo é calibrar a técnica de demodulação óptica utilizando dois filtros de transmissão fixos, procurando-se principalmente a posição verdadeira
Publicado em: 2007
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4. ANÁLISE DA TÉCNICA DE DEMODULAÇÃO BASEADA EM FILTROS FIXOS NA INTERROGAÇÃO DE SENSORES A REDE DE BRAGG EM FIBRAS ÓPTICAS / ANALYSIS OF THE DEMODULATION TECHNIQUE BASED ON FIXED FILTERS IN THE INTERROGATION OF FIBER BRAGG GRATING SENSORS
A análise da técnica de demodulação usada para interrogar sensores a rede de Bragg em fibras ópticas baseadas em filtros fixos foi realizada teoricamente e experimentalmente. Diferentes configurações de sistemas foram analisadas modificando a posição espectral dos filtros, assim como os níveis de potência óptica obtidos nos fotodetectores. Foram
Publicado em: 2004
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5. INTERROGATION SYSTEM OF FIBER BRAGG GRATING SENSORS USING TIME DIVISION MULTIPLEXING AND WAVELEGHT DIVISION MULTIPLEXING / SISTEMA DE INTERROGAÇÃO DE SENSORES A REDE DE BRAGG UTILIZANDO MULTIPLEXAÇÃO NO TEMPO E MULTIPLEXAÇÃO NO COMPRIMENTO DE ONDA
An interrogation system of fiber Bragg grating sensors using time division multiplexing and wavelength division multiplexing is proposed and demonstrated. The system presents a solution to measure the magnitudes associated to the reflection spectrum of the fiber Bragg gratings, making possible to increase the number of the Bragg gratings sensors monitored th
Publicado em: 2004
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6. Nova tecnica de processamento de sinais no dominio do tempo de giroscopios interferometricos de Sagnac a fibra optica
This work focuses on the study of a new time domain signal processing technique of Sagnac interferometric fiber optic gyroscopes. The technique consists in demodulating the output signal of the interferometer to obtain the rotation rate W and to monitor both the optical phase modulation depth m f and the incident power level 0 P , by measuring the dc value a
Publicado em: 2001
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7. Uma nova tecnica de detecção de sinais de giroscopio a fibra optica usando "Zero Crossing" com clock sincrono
The objective of this work is to study a new interferometric signal processing technique of fiber optic gyroscope based on zero crossing. A digital demodulation method was developed using this technique which allows the detection of a Sagnac phase difference, proportional to the system rotation rate, measuring time intervals difference determined by zero cro
Publicado em: 1999
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8. Projeto de um demodulador sincrono de frequencia utilizando o fenomeno "injection-locking"
This work proposes a new frequency demodulation technique using the principle of injection locking oscillation, with application to Broadcast FM and TV signals. It is well know that the signal generated by a nonlinear oscillating system can be synchronized to an external source when appropriated frequency and power conditions are present. This ?Locking? is k
Publicado em: 1991