A multi-layer frequency selective surface with bandwidth enhancement technique

Abstract

Frequency Selective Surface (FSS) is a two dimensional array with periodic structure. It acts as a filter. This project is aimed to design a band pass frequency selective surface at 5.8GHz with bandwidth enhancement. It is focused on three parts to reach the target. Firstly, the simplified design of the unit cell of frequency selective surface (UE-FSS) in the waveguide is proposed. Secondly, the bandwidths were enhanced by using different thicknesses of the substrates in the waveguide. Lastly, the arrays of frequency selective surface with different thicknesses of the substrate were constructed. All proposed designs were simulated by HFSS and done the fabrication. To get the measurement results of UE-FSS in the waveguide, there are two approaches. One is the size as same as the flange and the other is via hole around the size of simulating area. To get the measurement results of the arrays of FSS, there are also two approaches. One is the rotating the FSS horizontally in order to get different angles of response. The other is rotating the FSS vertically in order to get the different angles of polarization. By the simulations and measurements, these results are clearly showed that frequency selective surface (FSS) acts as a band pass filter at 5.8GHz. In addition, the thickness of substrate increases, the bandwidth also increases. It is true for the UE-FSS in the waveguide and the FSS.