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Abstract
Ultra-wideband (UWB) systems are recent systems that have significantly wider bandwidths than conventional systems. They have the potential for high data rate transmission which is very desirable in communication systems. They can also give high resolution in radar and localization applications. Several factors affect the operation of UWB such as the channel characteristics, difficulties associated with UWB signal processing and the transmission and reception of UWB signals through UWB antennas. A large number of UWB antennas were introduced in the literature such as TEM horns, UWB dipoles and monopoles and Vivaldi antennas. However, few attempts have been made to categorize these antennas and obtain physical insight into their operation. In this research, a comprehensive survey on some types of UWB antennas has been performed. Their principles of operation and reasons for their UWB operation are investigated. A method of moments, finite difference time domain and finite elements method codes were used to model these antennas and predict their performance. Two global optimization techniques were also employed to optimize these antennas.