Design of a sub-6 GHz cylindrical dielectric resonator MIMO antenna

Abstract This paper presents a multiple input multiple output (MIMO) system for sub-6 GHz using a two-port cylindrical dielectric resonator (CDR). This band is ideal for 5G applications, providing a balanced combination of coverage and capacity, as well as offering high data rates and low latency. The proposed MIMO is excited by an aperture-coupled feed structure composed of driven elements consisting of an elliptical-shaped step impedance transform line to enhance CDR coupling. Aperture coupling is used to excite the HEM 11δ mode without the involvement of any hybrid mode. The purpose of the aperture coupling in the CDR antenna is to launch the HEM 11δ mode, which is a magnetic dipole that provides a stable radiation pattern in the 3.2–3.7 GHz band, allowing for efficient transmission and reception of the data. Symmetrically oriented CDR and the presence of orthogonal fields provide good isolation, which can be further improved by the insertion of an asymmetric cross slot. The designed CDR-based MIMO antenna achieves excellent isolation of over 20 dB and demonstrates improved envelope correlation coefficient (ECC) values, resulting from low field correlation, across the entire frequency band of operation. Almost all the major diversity analysis was carried out for the desired sub-6 GHz band while maintaining a relatively compact size. Based on the measured results, it is confirmed that the proposed CDR-based MIMO antenna is appropriate for sub-6 GHz applications.