In this paper, we propose a microstrip line fed printed monopole antenna which has an ultra-wideband characteristic. Proposed antenna can improve the bandwidth characteristic with the taper structure formed by modified ground plane and radiating element. Measured impedance bandwidth ratio of the antenna is more than 30:1; from the lower frequency of 0.89 GHz to the upper frequency of more than 30 GHz for VSRW$leq$2. The antenna has conical radiation pattern that has low radiation gain to $ heta$=0$^{circ}$ direction and higher radiation gains as $ heta$ increases.