A Novel Miniaturized Ultra-Wideband Frequency Selective Surface With Rapid Band Edge

This paper presents a novel frequency selective surface (FSS) structure with miniaturized, rapid band edge, ultra-wideband (UWB) passband, and UWB out of band shielding. The proposed FSS is formed by using two air foam layers to cascade three single layers with the unit cell dimension in 6mm
$\times 6$
mm(
$0.023\lambda \times 0.023\lambda $
. The corresponding equivalent circuit models are developed for interpretation of the physical mechanism and formulate the relevant design equations. Finally, a prototype of the proposed structure is fabricated and measured to verify the full-wave simulation and theoretical analysis results. The measured results show the proposed FSS has a −3 dB passband from 1.17 GHz to 7.08 GHz and a −10 dB stopband from 7.34 GHz to 15.0 GHz. The corresponding relative bandwidths calculated from the measured results are 143.3% and 68.6%, respectively, which exhibits the stable performance against the variation of the incident angles from 0° to 45° for both TE and TM polarizations. All these results demonstrate that the proposed FSS is suitable for the actual miniaturized EMI shielding scene application.