Enhanced Performance of Compact Hybrid Space/Polarized Diversity MIMO Antenna System

Abstract

The work proposed in this manuscript is a 2×2 crossed planar microstrip configuration of a MIMO antenna for 5.8GHz WLAN applications. The antenna elements in the MIMO configurations have been isolated from each other using two different techniques. The first technique is using polarization diversity for the elements (using the orthogonal polarization technique), whereas the second technique is using a cross-defected ground for the four antenna elements. The single antenna element is a microstrip patch antenna, positioned and fed according to the polarization diversity. Thanks to the proposed design techniques, the proposed MIMO antenna has a good MIMO performance at the bandwidth centered at 5.8 GHz. An optimization process is performed by adding a DGS filter structure to the system, The use of the DSG reduced the mutual coupling from 20 to 41 dB between co-polar elements. MIMO system performance is evaluated through deriving MIMO parameters such as envelope correlation coefficient (ECC) and diversity gain (DG). Also, a channel capacity loss (CCL) is calculated for both MIMO configurations. Detailed figures for all derived parameters are illustrated. Finally, the used techniques have resulted in a compact MIMO with an overall size of 55 × 55 mm2.