en 5-Antenna Antenna Research Paper Research Paper Band-notch characteristic has been of great interest recently to overcome the electromagnetic interference of Ultra-wideband systems (UWB) with other existing ones. In this paper, we present a novel microstrip-fed antenna with band rejection property appropriate for UWB applications. Band-notch characteristic has been achieved by adding a rectangular resonant element to the ground section. A prototype was fabricated and measured based upon optimal parameters. Experimental results show consistency with simulation results. Measurement results confirm that the antenna covers the UWB band and satisfies a band rejection in the frequency span of 5 GHz to 5.7 GHz to restrain it from interference with Wireless Local Area Network (WLAN). Then, to achieve better isolation, a rectangular strip is appended to the band-notch creating part of the ground section to enhance obtained VSWR up to 30 through simulation. In addition, by applying a similar technique, a dual band-notched characteristic with an average simulated VSWR of around 13.75 has been achieved for WLAN and the downlink of X band satellite communication systems with each more than 10. Features such as small size, omnidirectional pattern and perfect isolation make the antenna suitable for any UWB applications. Band-Notch Characteristic,Radiation Pattern,Reflection Coefficient,Ultra-Wideband Antenna, 267 275 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-1019-1&slc_lang=en&sid=1 B. Zakeri zakeri@nit.ac.ir 180031947532846003162 180031947532846003162 Yes Babol Noshirvani University of Technology H. Bernety hossein_mehrpourbernety@ieee.org 180031947532846003163 180031947532846003163 No Babol Noshirvani University of Technology