Arranjos Log-Periódicos Compactos em Microfita com Elementos Fractais de Koch

• Ano de defesa: 2010
• Autor(a) principal: Almeida Filho, Valdez Aragão de
• Orientador(a): D'assunção, Adaildo Gomes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia Elétrica
• Departamento: Automação e Sistemas; Engenharia de Computação; Telecomunicações
• País: BR
• Palavras-chave em Português: Antenas de Microfita; Geometria Fractal; Arranjos de Antenas; Redução de Dimensões
• Palavras-chave em Inglês: Microstrip Antennas; Fractal Geometry; Antennas Array; Dimensions Reduction
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/15315

This work aims to present how the application of fractal geometry to the elements of a log-periodic array can become a good alternative when one wants to reduce the size of the array. Two types of log-periodic arrays were proposed: one with fed by microstrip line and other fed by electromagnetic coupling. To the elements of these arrays were applied fractal Koch contours, at two levels. In order to validate the results obtained some prototypes were built, which were measured on a vector network analyzer and simulated in a software, for comparison. The results presented reductions of 60% in the total area of the arrays, for both types. By analyzing the graphs of return loss, it was observed that the application of fractal contours made different resonant frequencies appear in the arrays. Furthermore, a good agreement was observed between simulated and measured results. The array with feeding by electromagnetic coupling presented, after application of fractal contours, radiation pattern with more smooth forms than the array with feeding by microstrip line