Design of $2\times 2$ Super-Wideband MIMO Antenna for S/C/X/Ku/K/Ka Band Communications

This paper proposes a novel four element super-wide-band multiple-input-multiple-output (MIMO) antenna. The proposed antenna design displays polarization diversity and radiates over wide range of frequency spectrum. Horizontal and vertically polarized patch radiators are spatially positioned in a perpendicular manner which contributes in achieving reduced mutual coupling and improved isolation greater than 20 dB with a highest value of 77 dB between adjacent and diagonal ports. Circular geometries are etched off from the bottom (ground) plane leading to an improved bandwidth. Parasitic structures in the form of circular hoops on the upper layer and Jerusalem cross on the bottom (ground) plane are added further improving the reflection coefficient(S11) parameters. The novel MIMO structure is based on FR4-epoxy substrate with dimensions 1.03
$\lambda^{\ast} 1.03 \lambda^{\ast} 0.014\ \lambda$
. The novel antenna thus radiates at frequencies 4.45GHz, 5.61GHz, 8.49GHz, 11.37GHz, 12.52GHz, 15.40GHz, 16.55GHz, 18.28GHz and 29.81GHz. The proposed novel design exhibits a super-wideband of 31.82 GHz and can be used for multiple wireless applications. Envelope Correlation Coefficient (ECC) value for the proposed design is less than 0.06 which shows good MIMO antenna performance.