Design and Analysis of a Dual Band MIMO Antenna for Improved Isolation using the Defected Ground Structure

A dual band compact MIMO (Multiple Input Multiple Output) antenna system is designed for the suited applications at S and C band. The designed antenna consists of two radiating elements with compact size of
$45\times 25\ \text{mm}^{2}$
. The designed antenna has the return loss of
$\vert\mathrm{S}_{11}\vert\leq-30\ \text{dB}$
at both of the resonant frequencies and to improve the isolation between the two elements defected ground structure is introduced. The simulated −10 dB impedance bandwidths are around 640 MHz (3.57 – 4.21 GHz), 750 MHz (6.29 – 7.04 GHz). In addition, the designed antenna has a VSWR value of ≤ 2 at the operating frequencies, and also has better diversity performance observed by low envelope correlation coefficient (ECC) and high diversity gain values.