## 4 Conclusions  
In this study, the novel designs of frequency-reconfigurable antennas incorporating ring resonators in conjunction with PIN diodes or RF switches are presented. These designs enhance the functionality, versatility, and adaptability of frequency-reconfigurable antennas in wireless communication systems. By changing the states of the switching components and with the presence of the ring resonator, precise control over resonant frequencies and bandwidths is achieved, enabling adaptation to various communication standards, frequency bands, and system requirements. The investigation demonstrates the \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & \multicolumn{1}{c}{
\begin{tabular}{c} **Dimension** \\ **(mm2)** \\ \end{tabular} } & \multirow{2}{*}{**Switching Element**} & \multirow{2}{*}{**Frequency Range**} \\ \hline
[50] & \(25\times 30\) & NA & \(2.34\)-\(5.5\,\mathrm{GHz}\) \\ \hline
[51] & \(100\times 100\) & Pin Diode (2) & \(2.2\)-\(5.5\,\mathrm{GHz}\) \\ \hline
[52] & \(14\times 36\) & Pin Diode (2) & \(2\)-\(6\,\mathrm{GHz}\) \\ \hline
[53] & \(25\times 27\) & Pin Diode (2) & \(2\)-\(6\,\mathrm{GHz}\) \\ \hline
[54] & \(50\times 45\) & Pin Diode (2) & \(2.5\)–\(5\,\mathrm{GHz}\) \\ \hline
[55] & \(30\times 30\) & Pin Diode (2) & \(1.8\)–\(4.5\,\mathrm{GHz}\) \\ \hline
[56] & \(33\times 16\) & Pin Diodes (3) & \(2\)–\(5.2\,\mathrm{GHz}\) \\ \hline
**This work** & \(25\times 18\) &
\begin{tabular}{c} Pin Diodes/RF switch (2) \\ and ring resonator \\ \end{tabular} & \(2.3\)–\(4.83\,\mathrm{GHz}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of the proposed antenna with the literature. effectiveness of these novel designs in achieving frequency reconfigurability. The antenna exhibits four distinct states, each offering their own resonance frequencies and operating frequency bands. State-1, suitable for mid-band 5G communication systems, operates at 2.4 GHz. State-2, characterized by a resonance frequency of 3.33 GHz, provides a single band characteristic. State-3 exhibits a bandwidth ranging from 2.59 GHz to 3.643 GHz, with a resonance frequency of 3 GHz, making it well-suited for Wi-Fi communication systems. Finally, State-4 covers an operating frequency band ranging from 2.95 GHz to 4.48 GHz. This redundancy in operating bands between State-1 and State-2, and State-3 and State-4, contributes to enhanced reliability. It ensures uninterrupted communication in dynamic wireless environments where interference or changes in the frequency spectrum availability may occur. The antenna can switch between similar states to maintain robust communication links, thereby enhancing overall system reliability. Moreover, the proposed designs offer several practical benefits. The ability to switch between states with similar operating bands can be strategically used to avoid interference from neighboring networks, optimizing the antenna's performance. Combining the bandwidths covered by similar states can lead to bandwidth expansion, advantageous for high-data-rate applications. The omni-directional radiation pattern characteristics of the antenna enable reliable connectivity in all directions within its coverage area, making it suitable for applications such as Wi-Fi, Bluetooth, IoT, and mid-band 5G. Furthermore, the comprehensive analysis of operating frequencies and radiation patterns demonstrates the antenna's adaptability to different communication applications. The proposed design controls the resonant behavior of ring resonators via switching components, achieving frequency reconfigurability and adopting various communication standards. This approach contributes to the development of compact, versatile, and high-performance antennas, facilitating efficient wireless communication systems across diverse applications. Overall, the integration of ring resonators and RF switches provides a robust mechanism for achieving frequency reconfigurability in the antenna, allowing it to efficiently adapt to different communication standards and bands.