Next-Generation Multiband Wireless Systems: A Compact CSSR-Based MIMO Dielectric Resonator Antenna Approach

This paper presents a compact penta-band Multiple Input Multiple Output (MIMO) Dielectric Resonator Antenna (DRA). The proposed MIMO DRA consists of two rectangular DRs incorporating complementary split ring resonators (CSRRs) and an inverted T-shaped slot. The MIMO DRA achieves low impedance matching through simple microstrip feedlines, which is further enhanced by integrating a microstrip line with the DRA itself. Remarkably, the introduction of CSRRs enables the design to resonate at five distinct frequency bands, namely 2.8-GHz, 4.4-GHz, 5.8-GHz, 6.4-GHz, and 6.9-GHz. The simulated properties of the MIMO DRA were validated through over-the-air measurements performed on a fabricated prototype. The proposed MIMO design demonstrates impedance bandwidths of 2.09 %, 2.43 %, 2.17 %, 2.55 %, and 4.91 % at the above respective resonance frequencies. The proposed design exhibits exceptional stability in radiation pattern, featuring a noteworthy peak gain of 6.08 dBi and an efficiency of 91.35 %. Notably, the incorporation of an inverted T-shaped slot effectively enhances isolation between the MIMO elements, achieving a maximum diversity gain of 10 dB and an envelope correlation coefficient of 0.005 over 20-dB isolation. A good agreement between the simulation and measured results is obtained, which underscores the suitability of the CSRR-based MIMO DRA for multiband wireless applications (blue tooth, radio astronomy, remote sensing, WIFI, satellite television and 6G), making it a very valuable contribution to the field.