Compact ultrawideband-reconfigurable antenna for cognitive radio platforms

A compact ultrawideband (UWB)-reconfigurable antenna for cognitive radio platforms is reported in this paper. The UWB antenna is a semicircular radiator with elliptical ground plane and is fed by coplanar waveguide (CPW) transmission line. A hairpin resonator is integrated on the ground plane of UWB radiator and can be treated as a reconfigurable band pass filter by changing its position and length. In addition, two PIN diodes are incorporated on both the arms of resonator as tuning element to switch to different communication band. The UWB antenna covers wide impedance bandwidth ranges from 1.9 GHz to 29.5 GHz, suitable for spectrum sensing application. On reconfigurable band state the antenna switching continuously from 9.2 GHz to 10.4 GHz with different state of operation of PIN diodes for the sake of communication. The simulated impedance bandwidth and radiation behavior for both the sensing and communication band demonstrates the design concept as a single port reconfigurable antenna for cognitive radio (CR) environment.