Miniaturization of a UWB antenna with dual band-notched at WLAN/WiMAX frequency bands

Abstract

In this paper, a highly compact symmetrical planar ultra-wideband (UWB) antenna with dual band-notched at the bands of the wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) is presented. The size of the antenna is strictly miniaturized both physically and electrically. The band notching of WLAN and WiMAX is achieved through the etching of two slots in the ground plane and the radiating patch respectively. Based on the symmetry of the antenna, additional size reduction is achieved by using only the half of the proposed antenna, while the antenna still does the same function except some minor changes in the band notching characteristics which can be optimized. The physical size of the antenna after reduction is 6.9×18 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> which represents an electrical size of O.07λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> X0.19λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> at the lowest frequency of operation. The antenna is properly matched to 50-ohm input resistance over the frequency band from 3.2-12 GHz. However, the frequency bands 3.4-3.8 GHz and 5.2-5.8 GHz are notched to mitigate the interference with WiMAX and WLAN technologies. The performance of the proposed full size and reduced size antennas is compared showing that the reduced size antenna has the same performance of the full size antenna.