This article presents the design and performance analysis of a printed microstrip ultra-wideband (UWB) antenna consisting of the slots in the ground plane and radiating patch. A meandered S-shaped slot has been introduced on the patch and an inverted U-shaped slot has been incorporated in the ground plane to realize the band-notch effect for WiMAX (3.2–3.8 GHz) and WLAN (5.1–5.8 GHz) bands respectively. The total dimension of the proposed design is 44 × 44 mm2. The fabricated antenna exhibits wide impedance bandwidth of 10 GHz (2.4–12.4 GHz), i.e., 135% of center frequency. The design prototype is fabricated, and the measured results have good agreement with simulated values. The effects of the slots have been analyzed by simulated surface current distribution. The designed antenna shows almost omnidirectional radiation patter and stable gain. The proposed hexagonal antenna may be suitable for UWB applications removing WiMAX and WLAN bands.