Design of circular and pyramidal shape reconfigurable UWB monopole antennas for cognitive radio applications

In this work a circular and pyramidal shape monopole antennas are made reconfigurable using same technique. Both of the antenna structure with circular and pyramidal shape is simple and easy to construct. Two parasitic metallic elements were used which are co-planar to each other. The reconfigurability is achieved from 3 GHz to 9 GHz frequency band. Three ideal switches between two metallic strips are employed to configure the resonant frequency of the proposed antennas in two different frequency ranges within the UWB frequency band. Results in term of reflection coefficient along with radiation pattern and gain are also discussed in this article. It is shown that this method of reconfigurability can be implemented to any other shapes to design UWB antennas.