Composite-structure frequency selective surface with tripole elements

Two composite symmetry structure is proposed in this paper. Based on the integral equation method, the frequency response with large incident angle effect is analyzed. As a result of the numerical analysis, it is shown that the composite symmetry structure with single FSS screen is efficient to stabilize the drift of FSS resonant frequency with the steering of incident angle though transmission loss increased. Especially the structure that the FSS is embedded centrally in the dielectrics has better frequency characteristic with flat top and sharp skirts. The studies have indicated the versatility of the proposed structure.