A Miniaturized Dual-Band FSS With Second-Order Response and Large Band Separation

In this letter, a miniaturized dual-band frequency selective surfaces with second-order band-pass response at each operation band is presented. The design is implemented by cascading a two-dimensional periodic array of double square loops and an array of wire grids. The proposed structure composed of three metal and two dielectric layers acts as a spatial dual band microwave filter with large band separation. The predicted FSS has the merits of broadband response, excellent stability for different incident angles, and sharp roll-off at X- and Ka-band, respectively. The simulation and measurement are carried out and further discussed. A good agreement between simulated and measured results verifies the design of the dual-band FSS.