[Paper] Advanced Liquid Crystals with Low Loss Tangent and Fast Response for Intelligent Reflecting Surface Antennas

Abstract

We are focusing our research attention on the improvement of performance for the intelligent reflecting surfaces (IRS) using liquid crystals. By realizing characterization of dielectric properties in liquid crystals using coaxial line in a wide range of frequency dispersion from 1 to 50 GHz, it is revealed that the 3-ring or 4-ring compounds possessing a high nematic-isotropic transition temperature exhibit the effects of reduction for loss tangent. For improving response time and loss tangent of IRS antenna using liquid crystals, low loss tangent reaching closely to 0.01 at frequency over 40 GHz band and shortening decay time for the response in almost half were achieved simultaneously by introducing para-terphenyl liquid crystal compounds without polar groups.