Abstract:A novel planar antenna with WiMAX and WLAN bandnotched characteristics is presented for ultra-wideband (UWB) applications. The UWB antenna consists of a staircase-shaped radiating element, a microstrip feedline and a modified ground plane. To realize WiMAX band-notched characteristic, a pair of hook-shaped slots is etched on the radiating element. Two folded stubs extending from the ground plane are used to reject the WLAN band for the first time. The antenna meets a bandwidth from 2.95 to 11.6 GHz, with two notchedbands of 3.25-3.95 GHz (WiMAX) and 5.00-6.50 GHz (WLAN), respectively. Measured and simulated results of the impedance bandwidth, gain, and radiation patterns are presented and discussed.