Uniplanar Differentially Driven Ultrawideband Polarization Diversity Antenna With Band-Notched Characteristics

A uniplanar ultrawideband (UWB) polarization diversity differential antenna with band-notched characteristics is presented in this letter for the first time. The antenna employs octagonal-shaped slot and two pairs of differentially fed monopoles being orthogonal to each other to achieve polarization diversity performance over the UWB. To effectively notch the 5.5-GHz WLAN band, the arc-shaped slots are inserted in the monopoles. As a result, the proposed antenna can achieve a wide impedance bandwidth of 143% (3-11 GHz) for the differential reflection coefficient less than -10 dB along with a notch band from 5 to 6.1 GHz. High differential port-to-port isolation of better than 40 dB and low cross polarization are also obtained by adopting a differential feeding mechanism. A prototype has been fabricated and tested. Results show that the antenna is very suitable for the applications in UWB wireless communication systems.