Aplicação de Células Metamateriais CLL ao projeto de antenas de microfita retangulares

Abstract

Obtaining and integrating solutions for technologies in the area of telecommunications has led researchers to investigate various materials, such as metamaterials in the construction of microwave circuits. Due to the ease of construction, microstrip antennas have used these materials that are not found in nature, as they have the possibility to manipulate their electromagnetic properties, making them interesting for the performance of antennas and various applications. In this context, the present work presents metamaterial cells and configurations in the form of periodic arrangements, immersed in the dielectric material, for the construction of the microstrip antennas. The analyzed antennas were designed for the operating frequency of 5.8 GHz. Simulations with the HFSS® software that uses the Finite Element method, were performed to analyze the electromagnetic characteristics of the cell and the parameters of the antennas, and thus investigating the influence of the arrangements in two case studies. Numerical results showed that the cell under study has a strong influence on the magnetic permeability in the metamaterial cell at the desired frequency. In the first case, there was a greater bandwidth and better impedance matching. In the second case, despite obtaining greater bandwidth, there was a decrease in the resonance frequency and a change in the impedance matching when the cells were rotated. To validate the results, prototypes were built for the first case under analysis and the measured results were compared to those obtained numerically, in which both showed good agreement. In the second study, only simulated results were obtained, considering the angle of rotation of the cells, ranging from 0 to 90 degrees with intervals of 15 degrees. For all the studied structures, the parameters the parameters analyzed were the reflection coefficient in dB (S11), bandwidth, polar and rectangular Smith chart, radiation diagram (2D and 3D), gain, Cross Polarization and Co-Polarization, as well such as the distribution of the electric field and the density of surface current.