A novel wideband crossed planar monopole antenna having the band-notched characteristic is presented. The proposed antenna consist of a wideband crossed planar monopole and multiple U-shaped slots, producing band-notched characteristic. In order to generate the band-notched characteristic on a crossed planar monopole, we propose that two or four U-shaped slots be required. This technique is suitable for creating an ultra-wideband (UWB) antenna with a narrow frequency notch or a multiband antenna. (c) 2006 Wiley Periodicals, Inc.