Small modified monopole antenna for UWB application

In this paper, we present a novel modified printed monopole antenna (PMA) for ultra-wideband (UWB) applications. The proposed antenna consists of a truncated ground plane and radiating patch with two tapered steps, which provides wideband behaviour and relatively good matching. Moreover, the effects of a modified trapezoid-shaped slot inserted in the radiating patch, on the impedance matching and radiation behaviour is investigated. The antenna has a small area of 14 x 20 mm(2) and offers an impedance bandwidth as high as 100% at a centre frequency of 7.45 GHz for S-11 < -10 dB, which has a frequency bandwidth increment of 18% with respect to the previous similar antenna. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behaviour within the UWB frequency range.