Abstract: A Coplanar waveguide-fed ultra-wideband (UWB) antenna was presented in the paper. The impedance bandwidth isabout 341%. The proposed antenna was printed on 28×21×1.6mm3 polytetrafluoroethylene with relative dielectric constant 2.65. Thekey parameters are simulated, analyzed and optimized using the electromagnetic simulation software HFSS. The ideal dimensions ofthe antenna are obtained. The optimized antenna was also manufactured and tested. The results show that the performance of CPWbroadband microstrip slot antennas can be greatly improved compared to traditional microstrip patch antennas, and the feasibility andeffectiveness of the CPW feed and the rectangle slot was also verified.