An integrated Ultra-Wide Band (UWB)/ reconfigurable slot antenna is proposed for cognitive radio applications. The
proposed antenna consists of an elliptical shape UWB disc monopole and a H-shaped slot resonator, which is precisely
embedded in disc monopole. The UWB antenna covers entire UWB band from 3.1 to 10.6 GHz and is used for channel
sensing. The H-shape slot resonator works as a narrow band antenna operating in the range 7.2 to 8 GHz. The slot is fed by
off-centered microstrip line that creates the desired matching across tunable frequency band. The proposed antenna
design is simulated using HFSS 15.