JCS_V1_N4_RP2 Siva Sundara Pandian S. C.D Suriyakala Journal on Communication Engineering and Systems 2277-5242 1 4 15 18 Cognitive Radio, Micro-Strip Patch, Polygon Patch, Sensing Antenna This paper presents about a new antenna design of ultra wide band antenna for cognitive radio wireless communication. This antenna consists of polygon on a printed circuit board; ground plane. This antenna was simulated in ADS (Advanced Design System) Momentum. The feeding point is the micro strip line and to this attached the polygon structure. A ultra wideband antenna is necessary in order to achieve the channel sensing which should possess an Omni directional radiation pattern. The ultra wide band antenna covers a spectrum from 5GHz to 12GHz for channel sensing. The resonant frequencies of the antenna are 7GHz and 9.77GHz. August - October 2012 Copyright © 2012 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/ArticleHTML.aspx?articleID=1980