A Miniaturized Dual-Band FSS with Closely Spaced Resonances Using 2.5-Dimension Structure

Using 2.5-dimension structure, a novel miniaturized dual-band FSS with closely spaced resonances is proposed in the paper. The special design of the geometry contributes to two closely spaced resonances at 1.69 GHz and 2.16 GHz respectively and the frequency ratio of upper to the lower resonant frequency is 1.27. Besides, the two bands can be controlled individually by varying corresponding parameters. The size of the proposed FSS is only 0.057λ , where the λ represents free space wavelength at lower resonant band. Furthermore, the simulation results show the proposed FSS exhibits stable response with different incident angles and polarizations. To understand the design better, the distribution of surface current is analyzed to explain the operating mechanism of the proposed FSS. Finally, the proposed FSS is fabricated and the measurement results are in accordance with the simulation results.