Demonstration of Multi-Band Frequency-Selective Surfaces Using Split-Ring Triangular Resonators

Design, experimental and modeling studies have been undertaken on periodic, multi-frequency two-dimensional arrays of four differently sized metallic split-ring triangular resonators fabricated on a dielectric substrate. A sample consisting of quadrants of four differently dimensioned resonators showed only a broadened, apparently multimodal feature in the transmission spectrum. Four discrete resonances were achieved using a number of permutations of a primitive unit cell containing each of the triangular resonators. For each of the unit-cell permutations, four discrete resonances are predicted based on numerical simulation; however, the spectral intensities are shown to be markedly different in a subset of cases.