Ultra wideband wide slot antenna with band-rejection characteristics

One of the challenges of the implementation of UWB systems is the development of a suitable antenna that would cover a large bandwidth, which would include some forbidden frequency bandwidth. A wide slot antenna with fork-shaped microstrip line fed structure [1] has been optimized for UWB applications; this prototype can cover whole UWB frequency range (3.1¿10.6GHz). The antenna is placed above a limited ground at a given distance to obtain a directive antenna. This paper presents different solutions to realize one or more filtering functions, to avoid interfering with existing 5.2/5.8 GHz wireless local area network (WLAN) systems for example. Two types of solutions have been studied: the first one is to modify the feed line of the antenna and the second one is to modify the radiating part.