Planar printed monopole antennas for ultra-wideband/multi-band wireless systems

An ultra-wideband (UWB) antenna with band rejection of WLAN/WiMAX systems and a tri-band antenna for WLAN/WiMAX applications are, respectively, proposed by the band-rejected design of the coplanar waveguide (CPW) fed circular monopole antenna. In order to notch the frequency bands covered by WLAN and WiMAX, two pieces of bent slotline are loaded at the patch bottom of the conventional UWB antenna. The proposed antenna has a good UWB characteristic with the measured notched frequency bands of 3.29-4GHz and 5.1-6GHz. In the new design of the tri-band monopole antenna, the slotline, resonant stub and radial slot are adopted to reject and control the frequency band of the conventional UWB antenna. This new tri-band monopole antenna renders the measured frequency bands of 2.25-2.8GHz, 3.3-3.8GHz and 5.1-5.9GHz for WLAN/WiMAX applications, and has a good band rejected characteristic in the other bands.