Desenvolvimento de uma sonda optoeletrônica para HF-VHF com compensação da variação da atenuação no enlace de fibra óptica plástica

• Autor(a) principal: Xavier, Odair da Silva
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/18859
• topic: Sonda eletromagnética; LED; Antena de laço; Fibra óptica plástica; Electromagnetic probe; LED; Loop antenna; Plastic optical fibers; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA::TELECOMUNICACOES::SISTEMAS DE TELECOMUNICACOES

This work describes the experimental development of an optoelectronics probe based on a passive, resonant and tuned loop antenna, for radio signals in the range of MF/HF/VHF, which shows the complete wave format for low frequencies (<45MHz). The light signal comprising DC and RF components is sent through a PMMA (poli methyl methacrylate) plastic optical fiber (POF) to a remote receiver. Three new aspects stood out in the development of the probe: low frequency operation, the use of the POF s technology together with LEDs, typically used in lightning and imaging, as well as the proposal and tests of a new technique used to compensate attenuation variations in the optical link. Near field tests were performed. The probe, when still not precisely calibrated, conveyed &#8776; 62.0 dBµv of dynamic range. Magnetic field strengths as lower as 2 nA/cm were detectable at frequencies responses up to 37 MHz. The probe has also been successfully tested with far fields, with field strengths as low as 0.8 nA/cm. A novel technique to compensate the attenuation variation of the fiber link up to 5.5dB has also been proposed, with successful tests results.