Designing a partially reflective surface for tri-band sectoral antennas

In this paper we present a novel approach to design a novel multi-band sectoral antenna by combining double layers Metallic Partially Reflective Surface (MPRS) as a superstrate with a Frequency Selective Surfaces (FSS) as a substrate, thus making it possible to circumvent the narrow bandwidth problem. We obtain the different operating frequencies by adjusting the distance of the lower MPRS layer from FSS layer and also the height between upper and lower MPRS layers. This antenna operates according to a sectoral radiation pattern form presenting a half power beamwidth of at least 60°. The proposed structure presents more than 16 dB directivity enhancement at 4.94, 5.25 and 5.65 GHz as compared to those of a patch antenna with 8 dB directivity. The geometry and characteristics of the antenna are detailed and a design method is proposed.