Abstract
In this study, we present an over-view on recent existing methods to generate UWB signals. Given the increasing interest in the UWB over optical fiber, special attention will be devoted to optical methods for generating UWB signals. These methods aim at ensuring a good integration of such radio signals over optical fiber with a very low cost. Some hybrid electro-optical methods will be covered before handling "all-optical" approaches. Particular attention will be given to the seven following methods: Chromatic Dispersion based approach, FBG-based approach, Optical impulse radio system, Electro-optical intensity modulator based method, Method based on XPM in an SOA, Optical FSK based method, and Spectral shaping and dispersion-induced frequency to time conversion based technique. For illustration some results will be presented.