A novel dualband frequency selective surface with periodic cell perturbation

A novel dualband frequency selective surface (FSS) with both a dielectric substrate and superstrate constructed by double-fourlegged loaded slots (DFLLSs) is investigated, in which each periodic cell consists of two neighboring DFLLSs with different dimensions, its resonant frequencies occur at 183 GHz and 220 GHz. Good selectivity performance can be easily achieved both in lower passband and higher passband by tuning the dimensions of the DFLLSs. Besides, the passbands are mainly determined by the neighboring perturb cells and can be designed independently. According to the explicit physical concept and some formulas, the design process become straightforward and simple. Its frequency performance is obtained by using numerical simulation software CST based on finite difference time domain method (FDTD). The simulated results show the good stability of the resonant frequencies and bandwidths at different polarization states and various incident angles.