In this paper, we suggested a CPW-fed UWB antenna with uni-planar sectoral structure. The area where radiation device face ground is designed to have the shape of tapered slot based on exponential function. We modified a rectangular bow-tie dipole structure antenna and thus formed a multi-resonant mode. From this, we expanded the impedance bandwidth and made a feature satisfying VSWR of less than 2 between $3.1sim10.6GHz$. The test result showed that the return loss less than -10 dB was met in the full-band UWB system and maximum gain of $0.9sim3.1dB$ was made with the half-power beamwidth of $40.1sim89.9^{circ}$ on XY plane(Theta, $Phi=90^{circ}$) and the full band. By using CPW-fed structure with no ground on the back of the substrate, the suggested antenna is easy to design and its miniaturization is also possible.