# Ultra-Wideband Compact Fractal Antenna for WiMAX, WLAN, C and X Band Applications
## 1 Introduction  
Globally, wireless communications are expanding rapidly. Given the speed of installation of wireless networks compared to that of building wired infrastructure to cover a specific area, wireless equipment is becoming more affordable and simpler to use [1, 2]. Microstrip antennas are the most widely used antennas to provide ultra-wideband operation. They have attracted significant attention from companies and universities in recent years due to their advantages such as low transmission power, high bandwidth, omnidirectional pattern, high data rate, and low price [3, 4]. In response to the need for compact and high-performance antennas, antenna designers have developed a new type of patch antenna that incorporates fractal geometries. Fractal geometries are composed of numerous segments that are precisely alike but with varying size scales. This concept was first introduced in 1983, and antenna designersare now utilizing it to create antennas that outperform traditional patch antennas. By combining fractal shapes with patch antennas, a multiband frequency antenna with high gain can be achieved. The incorporation of capacitive and inductive loads onto the patch surface enhances the antenna's frequency operation, resulting in a wider bandwidth and a multiband response. The need for wider bandwidth, multiband, and low-profile antennas is rapidly increasing, with both the commercial and military fields requiring multifunctional communication systems that can operate at multiple frequency bands. The literature describes many strategies for creating multiband operations to accommodate developmental requirements [5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]. In order to attain a larger working bandwidth and a smaller dimension, fractal geometry is applied in ref. [5]. Numerous fractal antenna methods exist for multiband operation, such as those of [PERSON] [6], [PERSON] [7], [PERSON] [8], [PERSON] [9], [PERSON] [10], the use of fractal tree antennas [11], the method of Cantor [12], and the use of shaped fractals [13; 14; 15]. As opposed to a regular antenna, which can only operate in one band, a fractal antenna can operate in several bands. Therefore, fractal antennas have many applications. With slotted antennas, good performance can be attained [16; 17; 18]. Fractals are recursive in nature [19; 20]. The self-similarity characteristic of fractal geometries facilitates the attainment of broadband and multiband properties. The characteristics of the fractal patch allow a change in the direction of the current flow and an extension of it over a longer distance, which results in the creation of new resonant frequencies and subsequently a UWB operation with radiation patterns and input impedance comparable to those of conventional antennas of a larger size. The authors of [21] created a fractal antenna based on the Cantor sequence that operates in the ISM band 2.40 GHz. The antenna is a suitable candidate for the medical field. [PERSON] and other authors in [22] used a dual-band fractal antenna with a bandwidth of about 500 MHz for breast cancer detection applications. A number of applications, including Wi-Fi, biomedical applications, C band, radar, satellite communication, and wireless computer networks, are covered by the work mentioned by [PERSON] and others [23]. In order to present an antenna with performance suitable for WLAN and WiMAX applications, the authors of [24] designed and manufactured a circular-slot antenna which functions over two frequency bands, 2.8-3.9 GHz and 5.2-6.2 GHz. Ref. [25] presents a miniature quad-band antenna that has a gain of 8.12 dB with 57 \(\times\) 31 \(\times\) 1.6 mm\({}^{3}\) reduced dimensions. The researchers of [26] used a 4 \(\times\) 4 MIMO antenna with four components placed on either side of the dielectric material to operate in the 2.40-2.48 GHz and 3.40-3.60 GHz bands. For dual-band wireless applications, [PERSON] et al. [27] describe the design of a slot-modified antenna.