An Improved Band-Rejection UWB Antenna With Resonant Patches and a Slot

Using two parasitic patches and a parasitic slot, we achieved a circular-slot type ultrawideband (UWB) antenna with excellent band-rejection characteristics. By changing the parameters of the parasitic patches and slot on the radiator, not only the rejection frequency but also the skirt and bandwidth of the 5-GHz rejection band can be easily modified without the degradation of the UWB antenna characteristics itself. Optimized parasitic patches and slot give the conventional circular-slot UWB antenna sufficient rejection bandwidth and sharp skirt response in 5-GHz rejection band.