DNG metamaterial-embedded multilayer FSS for substrate-specific EM profiling and ultra-wideband mm-wave suppression

This study presents a highly miniaturized, ultra-thin Multilayer Frequency Selective Surface (MFSS) engineered for ultra-wideband electromagnetic attenuation in mm-Wave systems. The design integrates three distinct resonator geometries within a vertically stacked multilayer structure composed of two identical Rogers RO4350B substrates with dimensions of about 4 × 4 mm 2 , 0.254 mm thickness, arranged with a subwavelength periodicity of 0.1834λ 0 . This resonator configuration achieves a synergistic stopband response with DNG characteristics, enabling a broad suppression range. An equivalent circuit model (ECM) is developed to analytically characterize its electromagnetic behavior, illustrating excellent agreement between the ADS and CST simulations, with resonance deviations below 1.5 % across all modes, confirming the high model accuracy and reliability of the proposed design. A fabricated prototype, consisting of a 20 × 20 unit cell array, demonstrates a measured rejection band from 15.6 GHz to 34.7 GHz, achieving a substantial fractional bandwidth (FBW) of about 76 %. Two transmission zeros (TZs) at 16.6 GHz and 31.68 GHz correspond to horn antenna interactions during experimental evaluation. The structure exhibits polarization insensitivity due to geometric symmetry, with oblique incident angle stability up to 60°. This MFSS enables in situ electromagnetic characterization with a maximum relative change of about 8.9 % for diverse materials embedded within the multilayer architecture, while affording spectral agility through resonator topology alterations and calibrated interlayer air–gap modulation. In this study, integrable nonlinear models, Bäcklund/bilinear methods, yield soliton and breather solutions that exemplify amplitude-dependent transport and robust localization, offering a physics template for field-dependent EM suppression in stratified media. With its compact form factor and exceptional suppression performance across Ku, K, and Ka bands, this DNG MFSS offers a high-performance solution for advanced mm-Wave applications, including 5G infrastructure, satellite communication, radar, and aerospace systems, and material characterization, outperforming conventional FSS designs in both performance and versatility.