In this article, a rectangular monopole ultra-wideband antenna with dual band-notched characteristic is proposed. The band-stop characteristic is produced by a new configuration of split ring resonators (SRRs). Being different from the conventional reverse split rings, this novel structure consists of two codirectional split rings and locates in the both sides of the rectangular radiating patch. Furthermore, the length of each ring controls the corresponding resonant frequency. By adjusting the dimension of the codirectional SRRs, the band-rejected frequencies from 3.25 to 3.75 GHz and from 5.15 to 5.6 GHz can be achieved easily. These rejected bands cover the operating bands, which have been applied to WiMAX and WLAN. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1032-1034, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24255