Frequency Selective Surface based on fractal structure with wide angular stability

This paper proposes a Frequency Selective Surface(FSS) with angular stability based on Minkowski fractal. The proposed fractal FSS structure consists of two layers of dielectric plates and three metal layers. The multi-layer FSS structure generates multiple transmission poles. Compared with the original FSS unit, the size of the fractal FSS unit is reduced by about 33.3% relative to the size of the wavelength at the resonance frequency point. The simulation results show that, compared with the original structure, the proposed fractal FSS has more stable angular response, wider bandwidth and the relative value of the resonant frequency offset achieves an average reduction of 52.0% under large angle of 70° oblique incidence.