DRAs have been widely recognized for their compact size, high radiation efficiency, and low profile, making them suitable for 5G sub-6 GHz applications. The study provides insights into the DRA design and performance optimization techniques for achieving dual-band and dual-circular polarization [17; 18]. The study in [19] presents a rectangular dielectric resonator antenna (RDRA) designed for a circularly polarized (CP) response in the 5G New Radio (NR) sub-6 GHz band applications. The innovation lies in a uniquely shaped conformal metal feeding strip that effectively excites the RDRA in a higher-order mode, leading to optimized high gain utilization. [PERSON] et al. discuss the manipulation of polarization states of electromagnetic waves using tunable metasurfaces [20]. The authors combine theory and experiment to demonstrate the capabilities of a tunable metasurface incorporating diodes as active elements to dynamically control the reflection phase of EM waves and manipulate the helicity of incident circular-polarized EM waves. The paper provides a detailed explanation of the experimental setup, results, and analysis, making it a valuable contribution to the field of optics and electromagnetic wave manipulation [20]. [PERSON] et al. discuss the use of the kirigami technique to create metamaterials that can control electromagnetic waves in a reconfigurable manner [21]. The authors introduce a kirigami-inspired sparse meta-architecture for adaptive invisibility based on independent operations of frequency, bandwidth, and amplitude. They demonstrate reconfigurable invisibility management with abundant EM functions and a wide tuning range using three enantiomers (A, B, and C) of different geometries characterized by the folding angle. The paper provides a new avenue for multifunctional smart devices [21]. [PERSON] et al. propose a novel formulation for the design of high-performance scattering metasurfaces through optimization-based explicit RCS reduction [22]. The authors discuss the recent advances in the development of coding metasurfaces and the potential benefits they offer in realizing radar cross-section (RCS) reduction. In the context of the antenna design, the ring resonator that supports resonant modes at specific frequencies has emerged as a valuable component in antenna design [23; 24; 25; 26; 27]. The ring resonator offers a range of possibilities for enhancing antenna performance and enabling frequency reconfigurability. This resonator introduces additional resonance frequencies that can modify the antenna's frequency response and radiation characteristics. By changing the parameters of the ring resonator, such as its dimensions, materials, or coupling method, the resonant frequencies can be controlled, providing frequency reconfigurability to the antenna. By utilizing the resonant behavior of the ring resonator, certain frequencies can be allowed and others blocked, allowing the antenna to operate in specific frequency bands. This capability facilitates frequency switching or filtering, enabling the antenna to adapt to different communication standards or frequency allocations. Furthermore, the ring resonator can be designed as a tunable element in the antenna structure. By incorporating tunable materials or active components such as varactors or MEMS devices into the ring resonator, the resonant frequency can be adjusted, allowing for frequency reconfiguration [11; 23]. The design of frequency-reconfigurable antennas with ring resonators can be accomplished by utilizing PIN diodes or Single-Pole-Double Throw (SPDT) switches. [PERSON] et al. focus on the design and application of metamaterial absorbers for various purposes, including sensing applications [26]. The research contributes to the field of metamaterial-based antenna design by proposing novel designs of multi-band and tunable absorbers that can be used for sensing applications, such as liquid refractive index sensing [27] and protein concentration measurement [28].