In this study, a new design of dual band-notched monopole antenna for ultrawideband (UWB) systems has been presented. The antenna consists of a pair of rotated T-ring strips protruded inside square-ring radiating patch, a feed line, and a ground plane with a pair of rotated E-shaped slot, which provides a wide usable fractional bandwidth of more than 140% with double band-stop performance. By applying the pair of rotated E-shaped slots in the ground plane, a new resonance at higher frequency range (14 GHz) is excited and much wider impedance bandwidth can be produced. In the proposed monopole antenna, to generate a single and dual frequency band-stop performance, we convert the square radiating patch to the square-ring structure with protruded T-ring strips. Simulated and measured results obtained for this antenna show that the proposed antenna offers very wide bandwidth from 2.65 to 15.1 GHz with two notched bands covering all the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX, and 4 GHz C bands. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:818–822, 2014