## 1 Introduction  
The evolution of communication systems over the past few decades has fundamentally transformed how we connect, share information, and access services. This progress has been further amplified by the advent of the Internet of Things (IoT), which has brought about a paradigm shift in the number of devices requiring connectivity [1, 2, 3]. The IoT is a cornerstone of modern wireless communication, fostering an interconnected world with intelligent, efficient, and scalable networks. It enables a connected ecosystem of devices,sensors, and systems [4]. The IoT leverages modern wireless technologies to facilitate seamless data exchange, automation, and intelligent decision-making across various domains, including smart homes, healthcare, agriculture, and industrial automation [5; 6]. As wireless communication evolves toward 6G and beyond, the IoT will remain at the forefront of technological innovation, driving the future of connectivity [7]. The rapid advancements in communication systems, coupled with the rise of the IoT, are redefining the expectations for handheld devices. The increased reliance on wireless services for seamless communication and data transfer has made it essential for modern devices to integrate multiple functionalities efficiently [8; 9]. Antennas, being critical components of wireless devices, need to adapt to these varying demands. This is driven by the increasing complexity of wireless devices, which must operate across multiple bands, support diverse applications, and be adaptable to changing environments [10; 11]. Reconfigurable surfaces are emerging as a potential solution for the aforementioned problems; however, their size and biasing complexity along with the power required are the challenges that need to be tackled [12; 13; 14]. Incorporating reconfigurability into antenna designs has emerged as a promising solution to these challenges by incorporating the ability to dynamically adjust their operating characteristics to meet specific system needs. Reconfigurable antennas can adjust their frequency, radiation pattern, or polarization to maintain optimal performance across different conditions [15; 16; 17; 18]. Frequency-reconfigurable antennas are a class of antennas that are capable of dynamically altering their operating frequency to support different communication bands. Thus, they mitigate the need for additional filters to stop the unnecessary bands [19; 20]. Moreover, these antennas are integral to modern wireless systems, which must operate across multiple frequency bands to accommodate various communication standards and applications such as 5G, LTE, the IoT, and satellite communication [21; 22; 23; 24]. The integration of frequency-reconfigurable functionality into a single compact structure eliminates the need for multiple fixed antennas, making them ideal for space-constrained devices like smartphones, wearables, and IoT sensors, thus reducing the manufacturing and design complexity. Frequency reconfigurability in antennas is achieved through various mechanisms that dynamically adjust the antenna's structure, electrical properties, or material characteristics. These mechanisms mainly involve switch-based reconfiguration (using PIN diodes and MEMS switches) [25; 26], tuning component-based reconfiguration (using Varactor diodes) [27; 28], material-based reconfiguration [29; 30], as well as mechanical alteration of the antenna geometry to achieve frequency reconfigurability [31]. Among the above-mentioned techniques for frequency reconfigurability, PIN diodes are widely used in antenna designs due to their characteristics such as their fast switching, reliability, and ease of integration. By acting as electronic switches, they enable dynamic changes in the antenna's operating frequency to meet the requirements of modern wireless systems. Moreover, PIN diodes are inexpensive compared to other switching technologies like MEMS.