Controle de feixe em antenas inteligentes utilizando geometria fractal ; Beam control in smart antennas using fractal geometry

Smart antennas are sets or arrays of antennas, linked to a signal processor, capable of adjusting or adapting their own beam pattern in order to emphasize signals or directions of interest and minimize signals/interferences or directions that are not of interest. Fractal antennas are radiating structures generated recursively and iteratively from the repeated application of a generator set factor, having the basic characteristic of being self-similar, that is, its structure on a larger scale is similar to the structures of the same antenna on a reduced scale. Based on the theory of fractals developed by Mandelbrot, they find application in almost all branches of science. The present work seeks to unite these two innovative technologies, smart antennas and fractal antennas, which, combined, can be an excellent alternative in projects that require greater bandwidth, adaptive beamforming, miniaturization and increased base station capacity. An extensive bibliographic study was carried out to give greater support to the topic in question. In addition, Ansoft®'s HFSS computational tool, a software that simulates high frequency structures, was used to simulate the proposed intelligent fractal antenna. Several simulations are performed and the results carefully evaluated. In the end, an arrangement composed of intelligent fractal antennas was reached, capable of performing a good scan of space and, at the same time, operating in multiband, an indispensable requirement for modern 5G systems. It is expected that the proposed smart fractal antenna can contribute to the design of communication systems that require greater spectral efficiency, meeting the growing demand for faster, safer and more economical connections. ; UFU - Universidade Federal de Uberlândia ; Tese (Doutorado) ; Antenas inteligentes são conjuntos ou arranjos de antenas, ligadas a um processador de sinal, capazes de ajustar ou adaptar seu próprio padrão de feixe de modo a enfatizar sinais ou direções de interesse e minimizar sinais/ interferências ou ...