Arranjo de antenas reconfigurável para 5G utilizando metamateriais

Abstract

The handheld devices for the fifth-generation (5G) of mobile communications will support diverse services using different frequency bands, including the Second Frequency Range (FR2), from 24.25 GHz to 52.60 GHz. This millimeter-wave (mm-waves) bandwidth provides high data rates, i.e. ≈2.15 Gbit/s for downlink and ≈2.37 Mbit/s up-link, however, the characteristics of the channels, devices manufacturing, and the high free space losses are some of the limiting factors of this frequency range. The network effectiveness will then depend directly on the use of high-performance antennas, reconfigurable devices, reduced costs, among other aspects. Taking advantage of the needs of 5G systems, this thesis presents a low-cost (initial prototype worth ≈250 reais), lightweight antenna array with reconfigurable two-dimensional beam steering (azimuth and elevation) to operate in millimeter waves. The main innovation is the antenna feed network based on metamaterials with low insertion loss, linearity operation, and reduced stage number. This network performs the beam steering through phase reconfiguration without interfering with the antenna array performance. Additionally, a parasitic patches technique was applied in order to improve gain and bandwidth. The project methodology is based on analytical calculations and numerical simulations were carried out using the software Ansys HFSS. The array performance has been analyzed in terms of the mutual coupling to evaluate its possible application in a multi-antennas system. The approach has a total size of 6×6 cm, compact enough to operate inside a mobile phone. All pre-set design requirements were achieved, resulting in an antenna array gain of 12.5 dBi, 2.8 GHz bandwidth, reconfigurability of 20∘, sidelobe level below 10 dB and mutual coupling lower than -50 dB.