Four-port MIMO cylindrical dielectric resonator antenna with FSS corner reflectors for gain and pattern diversity enhancement

This paper presents a four-port multiple-input multiple-output (MIMO) cylindrical dielectric resonator antenna (CDRA) with frequency-selective surface (FSS)-backed corner reflectors at 5.1 GHz to enhance performance. First, the single-port CDRA is investigated, and a monopole-type omnidirectional radiation is observed. To this end, a corner reflector with two FSS arrays is proposed to improve the gain and realize an increasingly directed radiation beam. The design can be further converted to a four-port by including an additional reflector, such that there are four corner segments. Using FSS as effective reflectors not only increases gain but also ensures good isolation, which is higher than 20 dB for all port combinations. The observed findings validate robust MIMO performance of the proposed antenna.