Dual-band frequency selective surfaces with higher-order band-pass responses

In this paper, a new technique for designing low-profile dual-band frequency selective surfaces, with second-order band pass responses, is presented. Using this technique, a dual-band response with a small separation between the two bands and high out-of-band rejection can be achieved. Similar to the structure reported in [6], the constituting elements composed of resonant elements and sub-wave length non-resonant elements. The combination of sub-wavelength unit cell dimensions and the small overall thickness of the proposed structure results in an FSS with a frequency response that is less sensitive to the angle of incidence of the EM wave.