Improved notch-band slot UWB antenna with small size

In order to minimize the potential interferences between the ultra-wideband systems and the narrowband communication systems effectively, a compact slot ultra-wideband antenna with assembled band notched structure is presented. A polygon slot on a printed circuit board is taken as the radiating element and is fed by a T-shaped stub. The overall size of the antenna is as small as 16 mm × 25 mm × 0.8 mm. The assembled band-notch structure formed by a C-shaped slit in the T-shaped stub and a rectangular slit embedded in the ground plane is implemented to shape a much sharper, wider, and deeper notch-band. Simulated and measured results indicate that the proposed antenna yields an voltage standing wave ratio (VSWR) of less than 2 in the impedance bandwidth range of 3.1 to 10.6 GHz, except the bandwidth of 5.0~6.0 GHz for band notch. Thus, the negative effect of WLAN on ultra-wideband system is eliminated effetively. Omnidirectional radiation pattern and stable gain are obtained in the whole bandwidth range.