A constant gain ultra-wideband antenna with a multi-layer frequency selective surface

摘要

An ultra-wideband (UWB) antenna with a novel multi-layer frequency selective surface (FSS) reflector is presented. A significant enhancement in the gain has been achieved in a low profile design while maintaining the excellent impedance bandwidth of the UWB antenna. The average peak gain of the antenna has been increased from 4 dBi to 9.3 dBi as a consequence of the use of the FSS reflector. More importantly the gain variation within the frequency range from 3 GHz to 15 GHz is only +/-0.5 dB. This is a significant improvement from §2 dB gain variation of the UWB slot antenna without the reflector. This optimized FSS re°ector provides the flexibility of mounting a planar antenna close to conducting bodies, including screens and cases