A novel design of reconfigurable monopole antenna with switchable triple band-rejection for UWB applications

In this paper, a new antenna has been proposed with dimensions of 28 x 28 x 0.8 mm(3) and the ability of operating in ultra-wideband (UWB) frequency and switching three notched bands. In the structure, to achieve the removal of characteristic of three frequency bands, a rectangular patch with an H-shaped slot on its surface and two C-shaped arms on its sides have been used. In addition, the designed antennas have the ability of operating in five different modes. To achieve the performance of reconfiguring, three pin diodes are used on the slots of rectangular patch and those two C-shaped arms. Also, with the defect ground structure and creating two rectangular slots and two L-shaped slots on the ground plane we make the excite of additional resonances and thus increase antenna bandwidth. Simulation and measurement results show that the designed antenna is able to cover the range of frequencies 3-12 GHz and a controllable frequency band rejection in the three frequency bands 3.2-3.75 GHz (WiMAX), 5.05-5.9 GHz (WLAN), and 8-8.45 GHz (ITU). The proposed antenna decreases the interference of the mentioned wireless systems with the UWB frequency.