Abstract: The author designed an ultrawideband antenna of a Ushaped floor semicircular ring feed terminal, and the effects on antenna performance of the parameters such as sector radius, inner diameter and the outer diameter of the semicircular ring, the length and width of the rectangle on the  Ushaped structure floor were analyzed. The antenna consisted of a semicircular ring feed terminal, a coplanar waveguide feeder and a Ushaped floor, coplanar waveguide was used to feed the antenna. The results show that the designed antenna has ultrawideband performance, the effective working bandwidth is 3—12.9 GHz, the design size is 20 mm×20 mm, the radiation characteristics and gain characteristics are good, so it can be used in ultrawideband wireless communication terminal system.

Key words:  , Ushaped floor, semicircular ring, ultrawideband, antenna