Efeitos do acoplamento mútuo em arranjos de antenas adaptativos para televisão digital.

Abstract

The antennas array can supply a high and controllable directivity, that is useful in communication systems, for instance, radar system, base radio station and connections point-to-point or satellite. The optimization of antennas array project is a task usually difficult, due to the no-linear characteristic of objective multiples, requesting the use of computational tools, such as the supervised algorithms (LMS and RLS). In that context, with the purpose of optimizing the electronic control of the space answer of antennas array, through the algorithms LMS and RLS, a computational tool was developed capable to position the main lobe and to reject interferences with known direction-of-arrival (DOA), taking into account, the effects of mutual coupling among the elements of the array. For so much, concepts of antennas theory and optimization methods were used, with emphasis in the LMS and RLS algorithms. The space answer of an adaptive array was analyzed for different dimensions and spacings, with the aid of LMS and RLS algorithms. A model of a linear array of antennas with four rectangular microstrip patch elements for use in the UHF band with applications in digital television (TV) is designed. The microstrip array operates at a frequency of 550 MHz. The microstrip array was simulated with the CST Studio Suite professional software, and results were obtained for the reflection coefficient and gain in the chosen frequency range.