Slotted ultra wideband antenna for bandwidth enhancement

In choosing an antenna topology for ultra wideband (UWB) design, several factors must be taken into account including physical profile, compatibility, impedance bandwidth, radiation efficiency, and radiation pattern. In this paper, a small compact T slots UWB antenna is presented. It originates from conventional rectangular monopole and is realized by adding T slots for both patch and feeding strip. The wideband behaviour is due to the fact that the currents along the edges of the slots introduce an additional resonance, which, in conjunction with the resonance of the main patch, produce an overall broadband frequency response characteristic. The slots also appear to introduce a capacitive reactance which counteracts the inductive reactance of the feed. Thus, the bandwidth broadening comes from the patch and T-slots, coupled together to form two resonances. The effect of current distributions of the T slots was simulated by using Zeland FDTD. The measured return loss of this proposed antenna is also presented as well.