A Novel Highly Selectivity Full-Frequency Protection Ultrawideband Polarization, Frequency, and Energy Selectivity Integrated Surface

Abstract

This communication proposes a novel, highly selective UWB surface for full-band, high-power protection. This design represents the first reported surface to integrate polarization, frequency, and energy selectivity functions into a single structure (HS-PEFSS). Crucially, this design eliminates the need for the air gaps conventionally used to control interlayer coupling, enabling a low profile and miniaturization. By incorporating interlayer coupling into the overall design through an equivalent circuit transformation, the modified equivalent circuit model (ECM) suppresses unwanted out-of-band transmission poles caused by interlayer coupling. This achieves the desired UWB out-of-band rejection (OBR), thereby integrating high-selectivity energy selectivity (ES) and frequency selectivity (FS). Further enhancement of polarization selectivity (PS) performance across the entire frequency band is achieved through inductive and capacitive suppression within the unit. To validate the exceptional performance of the proposed unit, an HS-PEFSS prototype suitable for both waveguide and absorber-screen free-space measurements was fabricated and measured. Simulation and measurement results demonstrate that the proposed HS-PEFSS achieves an IL of less than 1 dB in low-power transmission mode and an SE greater than 15 dB in the high-power shielding mode across a UWB range of 2.73–3.48 GHz. The 1-dB transmission bandwidth exceeds 24%. It features high out-of-band selectivity, with BW-LFOBS being 14.0% and BW-HFOBS being 8.25%. Furthermore, the proposed HS-PEFSS achieves SE greater than 15 dB and an OBR greater than 10 dB in the 0.4–2.25 GHz and 3.91–40-GHz bands for both x-polarization (x-pol) and y-polarization (y-pol), respectively. This HS-PEFSS demonstrates outstanding performance in terms of FS, ES, and PS.