Broad- and Narrow-band Frequency Reconfigurable Antenna for Cognitive Radio Application

Abstract

In order to improve spectrum utilization, a broad-and narrow-band frequency reconfigurable antenna for cognitive radio systems is presented in this paper. The antenna radiation patch is composed of two semicircles with different radii. The spiral slit is etched into a cut-angle rectangle ground plane, allowing the antenna to operate in narrow bands. Two PIN diodes are loaded in the slit, and their on/off states are controlled by the DC bias circuit on the front of the substrate. So that the resonant length of the slit is varied to achieve frequency reconfigurable. The simulation results show that the antenna can operate in three states, UWB: 3.82-12GHz, single band: 3.02-4.40GHz, dual band: 3.05-4.16GHz and 6.23-7.20GHz. The designed antenna has simple structure, small size (19×17.5×0.787mm3) and good radiation performance.