A Novel Tunable FSS of miniaturized unit cell for lower frequency

Large working bandwidth is now an attractive topic for FSS design, while it's hard to acquire a FSS structure with very wide bandwidth. So the way to actively tune the response frequency of the FSS, thus giving dynamic wide bandwidth maybe an available solution to this problem. In this paper, a two-layer structure loaded with variable capacitor was proposed to adjust resonance frequency. The upper layer employs strip lines and the lower layer joins capacitors between the cross rings to tune the frequency response curves of the whole structure quantitatively. This active frequency selective surface (AFSS) is sensitive to the change of loaded capacitance in some range while stay invariably above that, in which element can be regarded as being connected. Simulation results indicates that the rationality of analysis, which provides a general method to adjust resonance frequency and guides the active design of corresponding passive FSS in return.