A Band-Pass Frequency Selective Surface with Wideband Rejection Characteristic

In this paper, we propose a second-order bandpass frequency selective surface (FSS) with wideband rejection characteristic. The proposed FSS is composed of three periodic metallic arrays separated by two thin dielectric layers. In which, the top and the bottom arrays are composed of the complementary structure of the gridded square loop (C-GSL) elements, and the middle array is consisting of the wire grid. Performance of the proposed FSS has been investigated by the equivalent circuit model and full-wave simulations. The simulated results show that the proposed FSS can provide a passband operating at 9GHz and a stop-band ranging from 12GHz to 31GHz. Also, the frequency response of the FSS is stable at 60° oblique incidence for both TE and TM polarizations.