High‐gain, high‐isolation, and wideband millimetre‐wave closely spaced multiple‐input multiple‐output antenna with metamaterial wall and metamaterial superstrate for 5G applications

Abstract

Abstract A method to significantly increase the gain and isolation of a wideband multiple‐input multiple‐output (MIMO) antenna using metamaterial structures is reported. The proposed metamaterial medium includes just one wall and one superstrate, which are fixed in xz and xy planes of the MIMO antenna, respectively. The dimensions of the proposed MIMO antenna are 13×13×3.5 mm3 at 30 GHz. A comparison between a simulated MIMO antenna and a conventional microstrip antenna demonstrates the good performance of the proposed metamaterial environment. The corresponding return‐loss of the antenna is better than 10 dB over 28–32 GHz for 5G applications. The maximum simulated gain of the antenna is 17.1 dB at 30 GHz, generating a maximum gain enhancement of 11.8 dB in comparison with a MIMO antenna without any metamaterial structures. The isolation (insertion‐loss) is 36.7 dB at 30 GHz, which has improved by more than 29.4 dB compared to the conventional one.