Tanweer Ali, Subhash B K, Rajashekhar C. Biradar
2018 Progress In Electromagnetics Research C  
A miniaturized ultra-wideband (UWB) antenna based on Sierpinski square slots is reported. The antenna has a compact dimension of only 0.32λ l × 0.32λ l (28 × 28 mm 2 ), at a lower frequency of 3.4 GHz. Antenna miniaturization is achieved by etching Sierpinski square slots in the radiating decagonal shaped monopole, and UWB operations are accomplished by utilizing double truncations in the ground plane. The designed antenna has a fractional bandwidth of about 127. in simulation and about 124.7%
more » ... n and about 124.7% (3.50-15.1 GHz) in measurement. The time domain characteristics of the designed antenna are discussed in detail. Good radiation characteristics and impedance matching are exhibited by the designed fractal antenna in the entire UWB range. INTRODUCTION The recent years have witnessed a prompt growth in the wireless industry with tremendous-on-going research interest in the field of miniaturized UWB antennas. Higher spectral bandwidth and the necessity for high data rate based multimedia services with compact size pose major challenges on the conventional antennas [1] [2] [3] . With the allocation of UWB (3.1 to 10.6 GHz) by FCC, UWB communication systems have emerged as an alternative to narrowband systems, thus finding applications in indoor communications, wireless personal area network, remote sensing and radar imaging. UWB antennas provide high data rate communication in addition to low power consumption. Antenna miniaturization can be achieved by the use of slots [4-6], fractals [7], metamaterials [8, 9] , and Defected Ground Structure (DGS) [10, 11] . Ali and Biradar [12] proposed a miniaturized Volkswagen logo UWB antenna with a slot ground structure and circular Split Ring Resonator (SRR) for GPS, WLAN and WiMAX applications. Good gain and impedance bandwidth was obtained by employing an arc-shaped slot in a patch-based planar monopole antenna in [13] . Circular disc monopoles (CDM) were employed for achieving UWB operation in [14] , due to non-dispersive and good radiation properties. Slots in conjunction with feeding techniques such as CPW feed are employed to achieve UWB operation, due to the ability to suppress multipath fading and improved quality of service in [15] . Of late, the space filling properties of fractals have been incorporated into the antenna to achieve miniaturization. The space filling property of the fractals enables efficient package of electrically large features into a small area [16, 17] . Since electrical lengths play a major role in antenna design, such an efficient packing technique can be used as a viable antenna miniaturization technique. Anguera et al. [18] proposed a Sierpinski based compact monopole for mobile communications. Ding et al. [19] exploited the self-similarity property of fractals to design a multi-frequency antenna structure with UWB properties. Similarly, fractalization of the patch achieved a miniaturization up to 31.2% in [20] . Ghanbari et al. [21] used fractal geometries to miniaturize a circular disk monopole antenna, achieving miniaturization of more than 50% while preserving the UWB property. In this research, we present a new miniaturized fractal UWB antenna. The antenna consists of a Sierpinski square fractal slot in the radiating monopole to achieve miniaturization of about 46.3% and
doi:10.2528/pierc18040605 fatcat:pg52bwhqinbs3bcg7e5kouref4