A coplanar waveguide (CPW) fed ultra wideband slot antenna with reconfigurable band rejection characteristics is presented. Ultra wide bandwidth of 3.01-10.6 GHz is achieved by exciting the rectangular slot antenna with C-shaped stub. Band notch characteristic is changed between WLAN and WiMAX band by the integrated switches placed across the half wavelength slot. The performance of the proposed antenna is investigated numerically and experimentally. Experimental results demonstrate that the antenna exhibits omni directional characteristics with the peak gain of 4.9 dB and a gain variation of less than 2 dB across the operating band. © 2013 Allerton Press, Inc.