Millimeter-Wave Quad-Port Multiple-Input Multiple-Output Dielectric Resonator Antenna Excited Differentially by TE20 Mode Substrate Integrated Waveguide

In this paper, a differentially excited quad-element multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) is proposed for millimeter-wave applications. In the proposed design, the rectangular DRA is differentially excited in the TE
_1δ1
^y
mode using the dual-slot configuration located on the top wall of TE
₂₀
mode substrate integrated waveguide (SIW). The proposed MIMO configuration offers both spatial and polarization diversities. For all the four ports, the impedance bandwidth of the proposed antenna is 3.2% (27.5-28.4 GHz), covering the 5G frequency spectrum. The isolation between the input ports is better than 40 dB throughout the operating bandwidth. The antenna radiates along the broadside direction having the cross-polarization level below -30 along the zenith. The peak gain and radiation efficiency of the proposed antenna is 4.2 dBi and 86%, respectively at 28 GHz. Moreover, the diversity performance is found to be good having low value of envelope correlation coefficient across the bandwidth. The proposed antenna could be the potential candidate for next generation 5G communication system.