Compact Band-Rejected Ultrawideband Slot Antennas Inserting With \lambda/2 and \lambda/4 Resonators.

Two compact ultrawideband (UWB) slot antennas with band-rejected characteristics are proposed for UWB communication applications. The entire size of both antennas is as small as 15\ mm\times 22\ mm\times 0.8\ mm, which is smaller than most of the proposed UWB antennas. The radiator is a stepped slot excited by a 50 \Omega feed line. By etching a half-wavelength and a quarter-wavelength slot from the ground plane of UWB slot antennas, respectively, two UWB antennas with band-notched characteristics can be obtained. The potential interference between UWB and WLAN/WiMAX can be reduced. Omnidirectional radiation patterns and constant gain can be observed in the pass bands. Time-domain characteristics of both proposed antennas are analyzed under different conditions. It demonstrates that the time-domain characteristics of the antennas are good enough for UWB applications. The results show that proposed antennas are very suitable for various portable UWB systems. [ABSTRACT FROM AUTHOR]