An Ultra Wideband FSS Operating at Ka Band

An Ultra Wideband frequency selective surface (FSS) with forth-order bandpass responses operating at Ka band is proposed in the paper. To improve the performance of the FSS especially in angular stability, the coupling of capacitive surface and inductive surface is employed to realize the miniaturization of the structural unit around 0.26λ. Furthermore, to enhance the passband and to suppress sharply the bandstop edge of the FSS, a multi-layer FSS structure is adopted to form a forth-order filter. In addition, the FSS working at the Ka band frequency with a low-profile broadband and a high rejection stopband is designed. The proposed FSS can provide sharp frequency selectivity and stable frequency responses as functions of angle and polarization of incidence of the EM wave. Principles of operation, detailed design, and simulated results of the fabricated prototypes are presented and discussed in this paper.