Low terahertz transmission loss of polyphenylene sulfide/polyhedral oligomeric silsesquioxane nanocomposite foam for high-performance terahertz antenna

Abstract

The wireless communication industry is advancing toward higher-frequency electromagnetic bands, with the terahertz (THz) band emerging as the target for the next generation of wireless communication. However, the extremely high frequency within the THz band leads to significant signal loss in wireless communication devices (e.g., antennas), necessitating materials with ultralow dielectric properties. To address this challenge, this study developed a novel porous nanocomposite with ultralow dielectric properties by leveraging polyphenylene sulfide (PPS) as the matrix, integrating supercritical CO₂ (scCO₂) foaming and polyhedral oligomeric silsesquioxane (POSS) for low-dielectric modification, and optimizing PPS's foaming behavior through thermal oxidation treatment. Notably, POSS, as a unique component, introduces a complex coupling effect on the thermal oxidation process of PPS, significantly influencing its foaming behavior. By optimizing this coupling interaction, the obtained porous nanocomposite not only achieves a remarkable reduction in dielectric properties (dielectric constant of 1.2 and dielectric loss of 0.0016 @0.33 THz), but also demonstrates a substantial increase in THz transmittance from 65.9 % to 99.2 % (@0.33 THz). When applied to THz antenna, this porous nanocomposite elevates the THz signal transmission distance from 6.98 m (using pristine PPS substrate) to an unprecedented 387.4 m, showcasing a revolutionary performance breakthrough.