Proposta de uma nova estrutura multifractal com baixa sensibilidade da frequência de ressonância com relação à periodicidade

Abstract

Often, frequency selective surfaces have received wide attention from researchers around the world because of their filtering characteristics. These structures evolved in terms of manufacturing. Thus, the geometries used, initially, were yarns in the form of a grid and later, several types of new geometries such as: rectangular, square, circular, rings, square, etc., were used. Recently, fractals and, more recently, multifractal elements have been employed. The use of these geometries is done in order to obtain a specific frequency response. Important parameters such as bandwidth and resonant frequency are met from the use of a given geometry. In this work a multifractal geometry with double similarity is proposed, which has as main characteristic low sensitivity to the variation of the periodicity with respect to the resonance frequency. This specificity will bring gain with regard to the elaboration of the project, because the control of the bandwidth is made only with the change of periodicity. Several simulations were implemented in Ansoft Designer and for the purpose of proving, traditional structures were simulated, aiming at demonstrating the effect of periodicity on the resonance frequency, and then two prototypes were constructed and measurements were taken to experimentally validate the simulations.