## 1 Introduction  
Multiple antennas were used at the transmitter and reception sides of the multiple-input-multiple-output (MIMO) antenna system to improve system capability without requiring additional power. High separation among the radiating elements is needed to provide improved channel capacity. Because of the absence of side waves, as well as elevated radiation effectiveness, extreme gain, adjustable structure, and exciting mechanisms, dielectric resonators have become a viable alternative for MIMO antennas in recent years [1]. Only a limited investigation articles on MIMO DRA are available in the open literature [2, 3, 4, 5, 6]. A rectangular MIMO DRA for 4G applications has been proposed in ref. [2]. However, using a short brood and a cupper feed complicates the construction. For MIMO applications, [PERSON] et al. suggested a rectangular DRA [3]. through engraving cuts into the base plane, the separation among the ports has been increased. However, putting an RDRA in an FR4 substratum complicates the manufacturing process. For 5G NR band applications, the current authors proposed a cylindrical MIMO dielectric resonator antenna (CDRA) [4]. The isolation between the ports has been increased by activating the orthogonal mode in the CDRA. MIMO antenna based on DRA for radio access points has been offered in ref. [5]. The desired MIMO antenna can shelter the 2.45 and 5.8 GHz WLAN/5G NR groups with just one group of large and small DRAs.  
A MIMO RDRA for 5G NR band applications was discussed in ref. [6]. However, all of the MIMO antennas mentioned above have only shown linear polarization (LP). In recent years, antenna designers have become increasingly interested in using circularly polarized (CP) radiators in MIMO system antennas. Because circularly polarized (CP) antennas are preferred over LP antennas in wireless communication as they provide a consistent connection among the transmission and receipt systems irrespective of their positioning, ref. [7] demonstrates that, rather than employing an LP radiator, using a circularly Polarized MIMO antenna system appears to be a favorable technique in enclosed and outside conditions.  
During recent years, many studies have focused on decoupling methods, especially in UWB MIMO antennas through various complex, geometrical feed structures [8]. F-shaped stubs [9], metasurfaces using slots [10], and patch antennas [11] have been introduced to block the electromagnetic (EM) or current waves between radiators. However, the issue with all of these techniques is that they are a bit complicated to adopt; secondly, they are LP antennas. This paper proposes a singly fed, two-element, dual-port RDRA for MIMO and 5G NR band applications. The RDRA uses a modified, novel, A-shaped, conformal metal strip to generate CP waves. The conformal metal strip is oriented so that left-hand circular polarization (LHCP) is produced with one port, along with right-hand circular polarization (RHCP) is generated with the other. As a result, the polarization diversity concept is used in the proposed radiator to enhance the separation among the two radiator ports (\(\,\mathrm{I}\,\mathrm{S}_{\mathrm{12}}\,\mathrm{I}\,<-20\)). Several DGS cuts are employed in the base plane amongst the two antennas to further improve isolation (\(\,\mathrm{I}\,\mathrm{S}_{\mathrm{12}}\,\mathrm{I}\,<-25\)). The envelope correlation coefficient (ECC) and diversity gain (DG) are both used toward measure MIMO functioning.  
The following is the structure of the article: Section 2 provides details of the construction of the proposed antenna and its study. Section 3 covers the simulation results of the designs and optimization process. Section 4 presents the experimental results and diversity performance, and the conclusion is presented in Section 5.