An Aperture-Coupled Stepped Dielectric Resonator UWB MIMO Antenna With AMC

In this letter, an aperture-coupled stepped dielectric resonator (DR) ultrawideband (UWB) multiple-input–multiple-output (MIMO) antenna (UMA) is presented. The proposed stepped DR resonates with quasi TE
^x
_δ11
at 5.4 GHz and quasi TE
^y
_1δ1
mode at 6.4 GHz and merges with aperture resonating bands to achieve UWB. In the proposed orthogonal MIMO configuration, the stepped DR is able to improve the isolation in the higher frequency region and a modified neutralization line via a quarter wavelength square patch improves the isolation in the desired lower frequency region. The broadside radiating modes of the stepped DR and the dual artificial magnetic conductor (AMC) and PEC bands of the AMC reflector improves the gain and radiation characteristics. An improvement of 37.84% in gain stability within 2.3 dB variation (i.e., 4.2–6.5 dB) is achieved. The group delay of the UMA is more stable than the UWB antenna (UA). Thus, the problem of phase linearity is managed by multipath of the proposed UMA.