A band-notched UWB slot antenna with high skirt selectivity and controllable bandwidth

A compact ultra-wideband (UWB) antenna with sharp band-notched characteristics and controllable notched bandwidth is presented. The proposed antenna consists of an inverted U-shaped slot on the ground plane and a radiation patch similar to the slot which is fed by a 50-Ω microstrip line. By slitting an inverted U-shaped slot on the radiation patch and embedding an inverted U-shaped strip near the top edge of the ground aperture, a second-order notched band of WLAN (5.15-5.85GHz) is achieved. Compared with the traditional band-notched antenna, the selectivity of the notched band is greatly improved. Moreover, the bandwidth of either the lower or upper rejected band can be independently adjusted by changing the size of the slot and the strip, respectively. The antenna is fabricated on a standard low-cost FR4 substrate with a whole size of 27*20*1 mm3. Good agreement is achieved between simulated and measured results.