Design and investigation of a compact slot antenna with WLAN band rejection for UWB systems

A novel compact printed antenna fed by CPW with WLAN band rejection for UWB applications is proposed in this paper. This symmetrical antenna features three parts: a semicircular stub as the UWB radiator, a pair of modified compact patches which are integrated smoothly as the ground plane with the line-to-arc transition structures, and two U-shaped slots which are embedded on the ground plane to reject WLAN band radiations. This antenna with the miniaturized dimension of 25mm × 25mm × 1.5mm and excellent performance in frequency and time domains characteristics, has a VSWR less than 2 between 3GHz to 16.6GHz, stable H-plane omnidirectional radiation patterns, and constant group delay from 3GHz to 12GHz except the notched bandwidth of 5.05–5.88GHz. Good agreement between the measured and simulated results can be observed.