Four Port Dielectric Resonator based MIMO Antenna with High Isolation and Bidirectional Pattern Diversity

This letter introduces a four-port, bidirectional Al2 03 ceramic dielectric resonator based MIMO antenna. Two cylindrical ceramic dielectric resonators are positioned on the top and bottom sides of the FR-4 substrate separated by a certain distance and are excited with the help of a plusshaped coplanar waveguide feed such that the two consecutive CPW feeds on the two sides of the substrate are faced opposite to each other and constitute the antenna. The antenna possesses a dimension of
$60\mathrm{x}50\mathrm{x}10.6\text{mm}^{3}$
. The operating frequency band of the radiator is found to be 5.35-5.93GHz. The configuration of the feeding method employed in the proposed MIMO radiator allows the mutual coupling between the MIMO radiator's ports to be below -28dB within the operating frequency region. By exciting radiators positioned on the upper and lower side of the substrate, the proposed antenna achieves bidirectional pattern diversity. The MIMO antenna's diversity performance is observed to be within the allowable bound. The proposed radiator is applicable for a wireless local area network.