Spatially Uncorrelated Quad‐Port MIMO DRA With Negative Refractive Index Surface

ABSTRACT

A four‐port cylindrical dielectric resonator antenna (CDRA) with a negative refractive index surface (NRIS) to produce spatially separated radiation beams is presented in this letter. It is intended for multiple‐input multiple‐output (MIMO) applications. Two cylindrical dielectric resonators installed on the substrate's upper surface make up the suggested construction. Additionally, a metasurface made up of square split‐ring resonators placed regularly is used to achieve negative refractive index behavior in the 5.5–6.0 GHz frequency range. The NRIS integration increases the antenna system's overall MIMO performance and beam guiding capacity. An electromagnetic wave can change its direction of propagation when it enters a medium with a negative refractive index. Thus, beam tilting characteristics can be achieved with negative refractive index surface (NRIS). To achieve such characteristics, three similar NRIS arrays are integrated at an optimum distance from the CDR. The NRIS is positioned in such a way that four different patterns are originated from the proposed geometry. By employing this approach, the proposed antenna structure achieves port isolation better than 23 dB under all operating conditions. The obtained results demonstrate that the designed antenna provides effective isolation and stable performance characteristics, making it a promising candidate for 5.8 GHz WLAN band applications.