State of the art in ultra-wideband antennas

Ultra wide-band (UWB) technology is one of the most promising solutions for future communication systems due to its high-speed data rate and excellent immunity to multipath interference. In this context, the UWB antenna design plays a unique role because it behaves like a band pass filter and reshapes the spectra of the pulses, so it should be designed to avoid undesired distortions; some of the critical requirements in UWB antenna design are: ultra wide bandwidth, directional or omni-directional radiation patterns, constant gain and group delay over the entire band, high radiation efficiency and low profile. This work reviews the state of the art in UWB antennas, where planar monopole antennas show a special interest because they exhibit excellent performance in matching impedance bandwidth as well as pattern. Some experimental and simulation results on a proposed UWB antenna are also given.