Parametric analysis of different radii of concentric rings and substrates in frequency selective surfaces

In this study, the effects of the radii of the concentric rings and the substrate material on the spectral characteristics of the two concentric ring slot frequency selective surface structure are investigated by means of a finite integration technique and finite element technique based simulators. For the investigated dual band frequency selective surface structure, it has been demonstrated that the radius of the circular metallic patch and the inner ring slot affect only the resonance characteristics of the second stop band. However, the outer radius of the outer ring slot affects only the resonance characteristics of the first stop band. Tailoring the radius of the center metallic patch is found to be more useful for making fine adjustments in the spectral position of the second resonance band. The resonance frequencies of the stop bands can also be decreased if a substrate having a larger permittivity value is used.