Modelling Fully-Dielectric Metamaterial at 90GHz for Applications in the Sub-THz Band

This study introduces a novel semi-analytical circuit model for the comprehensive characterization of dielectric unit cells comprising T-shaped blocks, providing an alternative to conventional methods like the effective medium theory. By employing a fitting strategy, the model offers an in-depth understanding of the unit cell properties. The proposed semi-analytical approach exhibits very good agreement with the scattering parameters derived from full-wave simulations. Moreover, by varying the dielectric material, the model accurately captures the diverse behaviors of unit cells with different permittivities and electrical dimensions. As a practical application, transmitarrays designed to generate orbital angular momentum (OAM) waves were fabricated using 3D printing. Simulated results show favorable performance across multiple OAM modes at 85 GHz.