Tunable band gap properties of planar metallic fractals

摘要

We report the effect of finer structures, or more levels, in a particular type of planar metallic fractal pattern on the stop bands or band gaps in the transmission spectrum of electromagnetic wave. It is found that the band gaps shift to low frequencies with the increase of levels, showing tunable band gap properties. In addition, we find from both experiments and theoretical calculations that the bands appearing in long wavelength range are determined by individual patterns which compose a 6×6 fractal array, while those bands located in the range of short wavelength are strongly influenced by their neighboring residents. Our experimental observations are in good agreement with those of finite difference time domain simulations.