Reconfigurable monopole Antenna withDefected Ground Structure for CognitiveRadio Application

The proposed microstrip-feed antenna mainly consists of circular monopole antenna (CMA) with defected ground structure for cognitive radio application is presented. The proposed antenna uses FR-4 substrate having thickness of 1.6mm and dielectric constant of 4.4. This antenna achieves an enhanced impedance bandwidth of 2.98GHz. Most of the work in cognitive radio domain has been done in the frequency range of 3.1GHz to 10 GHz, but this paper presents a CMA operating over frequency band of 0.6GHz to3.58GHz. The proposed antenna was designed and analyzed by using software HFSS (Higher frequency simulation software) 13.0 which is suitable for cognitive radio applications.