Abstract: Nowadays, UWB antennas and reconfigurable antennas are both hot research fields.In this paper, the technology of reconfigurable antenna is applied to ultra-wideband antennas, and the basic design idea of frequency reconfigurable UWB antenna is discussed.Based on the elliptical planar monopole antenna, two reconfigurable UWB antennas are presented.In order to avoid interference with other communication band, an antenna is designed with a reconfigurable bandnotch. The simulation results of antenna Ⅱ show that after reconfiguration, the LF band is extended.Simultaneously, the length and width of relative size are reduced to 0.116 and 0.087 times of the maximum operating wavelength.The antenna Ⅱ operates at 0.174~10.9 GHz, and the reconfigurable notched band is 5.1~5.95 GHz.Moreover, the bandwidth ratio is 62:1.