Yüksek İzolasyonlu MIMO Anten Dizisi İçin FSS Duvar Tasarımı

Abstract

In MIMO antennas, mutual coupling that adversely effects antenna performance is due to the surface currents. To date, many techniques such as Electromagnetic Band Gap (EBG) structures, metamaterial unit cell, band-stop filters and Frequency Selective Surfaces (FSS) have been proposed to suppress these surface currents. FSSs, when properly designed, can act as a band-stop filter in a given frequency range and thus prevent the propagation of these surface waves in the microstrip patch arrays. In this study, a new FSS unit cell is designed to reduce the mutual coupling effect caused by surface currents between two identical 2x1 patch antenna arrays with a 3.49 GHz operating frequency. These designed FSS unit cells are placed between the patches with a 1x5 periodic sequence. According to the simulation results, mutual coupling effect decreased by 26.6 dB without any shift in the transmission band with only 0.48 dB change in S 11. Finally, Envelope Correlation Coefficient-ECC curves are plotted separately for the antenna array with and without the FSS wall. It is observed that the ECC of the antenna array is dropped from 0.16 to 0.07 by applying the proposed isolation wall.