Bandwidth Enhancement using Stacked Patch MIMO Antenna with Low Mutual Coupling for 3.5 GHz

In this paper, this proposed stacked parasitic patch is presented for 3.5 GHz MIMO antenna mobile application. The parasitic patch is placed on top of the radiator patch. The MIMO antenna is composed of four rectangular antenna elements on a compact size of FR 4 with a
$\mathbf{156\ x\ 40} \mathbf{mm}^{2}$
and total thickness of the stacked MIMO antenna is 3.84 mm. The presence of parasitic patch contributes to improve the performance of MIMO antenna with low mutual coupling including impedance bandwidth, VSWR and S-parameter. There is a 42.57% improvement of impedance bandwidth through 3.3949 GHz to 3.7214 GHz (326.5MHz). VSWR values less than 2 along impedance bandwidth spectrum and the lowest VSWR is 1.11 at 3.5 GHz. In addition, this proposed stacked MIMO antenna also has good ECC (less than 0.02) and diversity gain (more than 9.98) at an operating frequency of 3.5 GHz.