Highly Isolated Hexagonal Shaped DGS based MIMO Antenna for C-Band Applications

In this article, we present a miniaturized wideband multiple-input multiple-output antenna with high isolation for C band use. It consists of 2×1 hexagonal motifs which serves as radiating elements. Defected ground structure (DGS) technique is employed to attain an efficient isolation between the antenna elements. Two inverted L-shaped stubs are incorporated to enhance the isolation and reduce the antenna size enlargement simultaneously, by suppressing the surface waves. The overall dimension of the designed MIMO antenna is 30 × 20 mm². The proposed DGS structure provides - 40.81 dB of isolation at 7.88 GHz and a gap of 4 mm between adjacent antenna elements. Envelope correlation coefficient (ECC) is less than 0.01, diversity gain (DG) greater than 9.95 dB, total active reflection coefficient (TARC) less than 0.4, mean effective gain (MEG) less than -3 dB, and channel capacity loss (CCL) less than 0.4 is achieved. Besides, scattering matrix such as return loss S11 and transmission coefficient S21 between two elements, radiation pattern, and current distribution was also favorable for C-band and X-band applications.