Bandwidth Enhancement of a Wide Slot Antenna Using Fractal Geometry for UWB Application with Multiple Notched Bands

In this paper a combination of rectangular and elliptical fractal geometry is applied on a regular hexagonal wide slot antenna fabricated using a FR4 substrate to obtain ultra wide band (UWB) operation. The bandwidth enhancement of the wide slot antenna due to this fractal curve is studied in a step by step manner and the corresponding mathematical analysis is also presented. The comparison of the proposed fractal geometry with the existing fractal geometries is also exhibited. Multiple input multiple output performance of the proposed UWB antenna is also analysed. Two pairs of L-shaped slots are etched on the ground plane and a metallic ring is inserted inside the slot to produce triple band notch characteristics at 3.98 GHz, 5.56 GHz and 7.94 GHz. These three notch bands can avoid interference with existing WIMAX, downlink of C-band satellite communication, WLAN and uplink of X band satellite communication. The proposed band notched UWB antenna exhibits acceptable radiation characteristics with satisfactory gain, high radiation efficiency and constant group delay in the operation band.