# A Multi-Bandwidth Reconfigurable Patch Antenna for Devices in WLAN and UWB Technology Applications
## 1 Introduction  
Patch antennas (PAs) consist of a thin metal patch placed over a ground plane, with a feed point connected to a transmission line. They are directional antennas and can operate at different frequencies based on their size and shape. Over the last few years, they have become increasingly popular due to their small size, low profile, and ease of integration with other electronic components [1; 2], compared to traditional antennas. Their small size, high gain, and robustness are features that are highly valued in the fields of mobile device fabrication and wireless communication systems, where they are widely used. There is ongoing research to design compact and efficient PAs that are capable of supporting high-speed data transmission so they can be included in micro-electromechanical systems (MEMS) that can be integrated into small devices [3; 4; 5; 6; 7; 8]. In recent years, advances in material technology and manufacturing techniques have led to the production of patch antennas with even smaller dimensions and higher performance [9; 10; 11; 12; 13]. The quest for further reduction in PA sizes remains a research field with open challenges, where new miniaturization techniques are under development [14; 15; 16; 17]. In wireless communication systems, there are two common types of antennas: ultra-wideband (UWB) and multi-band antennas [18; 19; 20; 21]. While both of them are designed to cover a wide range of frequencies, they differ in their features and applications. Multi-band antennas consist of several resonating elements; each tuned to a different frequency band, and designed to operate across multiple narrow frequency bands. Multi-band antennas are suitable for applications that require communication over multiple frequencies, such as cellular networks and Wi-Fi systems. On the other hand, UWB antennas are designed tocover a wide spectrum using a single resonant element [22; 23; 24; 25]. They operate over a broad frequency range without the need for multiple resonators. In this context, reconfigurable planar antennas have become increasingly popular due to their ability to switch between different modes of operation, frequencies, and radiation patterns, combining characteristics of both multi-band and UWB antennas. They are commonly used in modern wireless communication systems that require a wide range of frequencies, such as ultra-wideband (UWB) [26; 27; 28] and wireless local area network (WLAN) applications. In recent times, a few approaches have been reported in the literature to achieve UWB characteristics: tree-like fractal slots [29], compact folded network antennas [30], reconfigurable antennas using diodes on an FR4 substrate [31; 32; 33], fractal arrays [34], and MIMO (multiple-input multiple-output) antennas [35; 36]. The use of reconfigurable components, such as PIN diodes, as in ref. [33], allows the antenna to switch between different frequency bands, enabling it to adapt to different communication requirements. The design of this type of antenna is challenging and requires the use of electromagnetic simulations and optimization techniques to achieve the desired performance. In this paper, we present a rounded rectangular reconfigurable patch antenna that can support both the UWB application and the WLAN band, where the reconfigurability is achieved by using PIN diodes to switch between different resonant modes. It incorporates one notch band to create a band for the UWB frequency bands and two additional resonant elements to create a band operation for the WLAN frequency bands, with a hybrid shape slot composed of a circle and a rectangle. The hybrid-shaped design reduces the overall size of the antenna while maintaining a satisfactory level of performance in terms of bandwidth and radiation efficiency. The circular shape provides transverse radiation patterns, whereas the rectangular shape helps reduce cross-polarization. This article is structured into four sections. In Section 2, the proposed antenna's design geometry and its various development stages are explained.