Isolation Enhancement for MIMO Dielectric Resonator Antennas Using Dielectric Superstrate
Min Li, Singwai Cheung
Abstract
This communication proposes a novel decoupling approach for multiple-input multiple-output (MIMO) dielectric resonator antennas (DRAs) using a dielectric superstrate above the array. Utilizing the interaction with electromagnetic fields, the superstrate affects the coupled field distributions inside the adjacent DRA and so reduces coupling between two closely located DRAs. Five decoupling cases are investigated to show the advantages of this method. Results show over 25 dB isolation enhancement for all cases. Good radiation characteristics are obtained with the improvements in total efficiency and realized gain and reductions in envelop correlation coefficient and pattern slant angle. Moreover, the superstrate is independently designed and implemented above the coupled array without requiring modification on the original array. Therefore, the proposed one provides a unique approach for isolation enhancement of MIMO DRAs.