Isolation and Bandwidth Enhancement of 5G Millimeter-Wave Dual-Band MIMO Antenna Based on Metamaterial Wall

An isolation- and bandwidth-enhanced 5G mmwave dual-band MIMO antenna is proposed. The proposed antenna composed of a 2×1 28/38GHz dual-band antenna and a metamaterial-based isolation wall. On the one hand, the isolation improvement is achieved by the dual-band bandstop characteristic of the isolation wall. On the other hand, after inserting the isolation wall, the input impedance in both low-and high-band is improved simultaneously. Simulated results illuminate that the isolations at low- and high-band are improved by 26dB and 39dB, respectively. Meanwhile, the operating bandwidths <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\vert \mathrm{S}_{11}\vert &lt; -10\text{dB})$</tex> are largely increased from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$27. 7\sim 30.4\text{GHz}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$36. 1\sim 41.0\text{GHz}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$27. 0\sim 30.3 \text{GHz}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$35.2\sim 45.9\text{GHz}$</tex>, resulting in the bandwidth extensions of 24% and 108%, respectively. The proposed MIMO antenna has the advantages of high isolation, wideband and dual-band operation, which can be used for the 5G millimeter-wave wireless communication system.